The Case of Fur Color Evolution in Beach Mice or

The Case of Fur Color Evolution in Beach Mice or
Slide Set Available from The Case of Fur Color Evolution in Beach Mice or

Wouldn’t it be nice if I had white fur???

Anatomy of a Hair Follicle
The hair shaft is made of cornified cells – that is, dead cells filled with keratin. Within the region of matrix stem cells are specialized pigment-producing melanocyte cells. Melanocyte cells Image adapted from:

Image: http://www. dermnetnz. org/doctors/principles/images/hair-bulb

Hair Color Two pigments Eumelanin Pheomelanin Pheomelanin Eumelanin
Melanocyte cells Pheomelanin Roland Mattern Eumelanin Roland Mattern Image adapted from:

Hair Color Dark Hair: Lots of eumelanin
Fair Hair: More pheomelanin, less eumelanin Red Hair: Lots of pheomelanin If there is not enough cAMP, dopaquinone binds to cysteine and the product , cysteinyldopa, continues on a biosynthetic pathway that results in pheomelanin. If there is lots of cAMP, the four genes [c(tyrp), Tyrp1, Tyrp2 and p] are all expressed and dopaquinone is converted into leucodopachrome. This results in a biosynthetic pathway that results in melanin.

How is melanin produced?
Transmembrane proteins that are stimulated by a hormone. When these melanocortin receptor proteins are stimulated…. LOTS of eumelanin is produced.

Stimulation of MC1R leads to lots of cAMP production.
cAMP leads to the expression of at least four genes: c(tyr), Tyrp1, Tyrp2, p c(tyr) Tyrp1 Tyrp2 p Image from:

cAMP leads to the expression of at least four genes: c(tyr), Tyrp1, Tyrp2, p MC1R stimulation leads to lots of cAMP production which means Tyrp1, Tyrp2 and p are expressed lots of eumelanin. c(tyr) Tyrp1 Tyrp2 p Image from:

cAMP leads to the expression of at least four genes: c(tyr), Tyrp1, Tyrp2, p Inadequate MC1R stimulation leads to less cAMP production which means Tyrp1, Tyrp2 and p are not expressed  less eumelanin; more pheomelanin. c(tyr) Tyrp1 Tyrp2 p Image from:

cAMP leads to the expression of at least four genes: c(tyr), Tyrp1, Tyrp2, p MC1R is a pretty big deal. c(tyr) Tyrp1 Tyrp2 p Image from:

Eumelanin and Pheomelanin
Images from:

The Natural History of Fur Color in Beach Mice
1.0 The Natural History of Fur Color in Beach Mice ** Notes on the slides in this section: The following few slides are included as an overview of the natural history of beach mice. For more information visit: Two questions are included that could be the basis of student discussion or an interactive engagement activity.

Fact Sheet: Peromyscus polionotus
1.1 Fact Sheet: Peromyscus polionotus Common names: Beach Mouse or Old Field Mouse. Location: Southeastern U.S.A. Habitat: Sand burrows in dunes or old fields. Home-range: ~1000 m2 Breeding: Monogamous pair- bonding. Litters of 2-8 pups, every 30 days. Lifespan: 9-12 months. This is a basic fact sheet of Peromyscus polionotus. The range of P. polionotus is shown on the map in red.

allophrys/peninsularis
1.2 Fur Color Subspecies: leucocephalus trissyllepsis allophrys/peninsularis ammobates subgriseus There are several sub-species of beach mouse. Each population has a slightly different coat color. Sub species tend to be geographically isolated from one another. For more details see:

How are populations of these sub species distributed within the range of the Beach Mouse?
1.3 ? ? ? ? ?

The Spatial Distribution of Fur Color
1.5 The Spatial Distribution of Fur Color This shows where several of the different subspecies live. The darkest colored subspecies tends to live inland while the lighter subspecies live on light sand beaches. Lighter colored sub-species live on light sand beaches; darker colored sub-species live in darker habitat.

1.6 Question Assuming that ancestral populations of beach mice had dark brown fur, what could have happened to explain the occurrence of light-colored coastal sub-species? The purpose of this activity is to have students brainstorm the spectrum of proximate and ultimate cause for the change in mouse fur color amongst P. polionotus subspecies.

The Melanocortin-1-Receptor (MC1R)
What can you tell me about the MC1R protein? Write three things down.

What can you tell me about the MC1R protein? Write three things down. Do you think there are any differences between the MC1R protein of dark haired mice and the MC1R protein of light haired mice? If so, what? Write something down.

What can you tell me about the MC1R protein? Write three things down. Do you think there are any differences between the MC1R protein of dark haired mice and the MC1R protein of light haired mice? If so, what? Write something down. Do you think there are any differences between the mc1r allele of dark haired mice and the mc1r allele of light haired mice?

Consequence of Mutation
4.6 Consequence of Mutation There is a change in the the amino acid identity at position #67: an Arginine vs. a Cysteine Amino Acid Sequence Dark Fur: MPTQGPQKRLLGSLNSTSTATPHLGLATNQTGPWCLQVSIPDGLFLSLGLVSLVENVLVVIAITKNRNLHSPMYSFICCLALSDLMVSISLVLETAIILLLEAGALVTRAALVQQLDNVIDVLICGSMVSSLCFLGVIAIDRYISIFYALRYHSIVTLPRARRAIXGIWVASIFFSTLFITYYNHTAVLICLVTFFLAMLALMAXLYVHMLTRAYQHAQGIAQLQKRQGSTXQGFCLKGAXTLTIILGIFFLCWGPFFLHLTLIVLCPQHPTCSCI FKNFNLYLVLIIFSSIVDPLIYAFRSQELRMTLREVLLCSW Note – there is more than one difference in the two above sequences. However, the single change at position #67 is the only difference in these sequences that is associated with the change in coat color. Amino Acid Sequence Light Fur: MPTQGPQKRLLGSLNSTSTATPHLGLATNQTGPWCLQVSVPDGLFLSLGLVSLVENVLVVIAITKNCNLHSPMYSFICCLALSDLMVSISLVLETAIILLLEAGALVTRAALVQQLDNVIDVLICGSMVSSLCFLGVIAIDRYISIFYALRYHSIVTLPRARRAIVGIWVASIFFSTLFITYYNHTAVLICLVTFFLAMLALMAILYVHMLTRAYQHAQGIAQLQKRQGSTRQGFCLKGAATLTIILGIFFLCWGPFFLHLTLIVLCPQHPTCSCI FKNFNLYLVLIIFSSIVDPLIYAFRSQELRMTLREVLLCSW

Freeman 4e Fig. 15.4

Substitution Mutation
A single nucleotide substitution mutation in the mc1r gene causes a change in amino acid #67 in the MC1R protein chain. When amino acid #67 is cysteine, the MC1R protein is unable to effectively bind the α-MSH. This changes the pigment pathway and eumelanin is not produced. The next several slides to through this information in a step-by-step manner. You can decide how you would like to teach this material depending on the level of your students.

mc1r Gene Sequence Let’s look at what happens when ONE SPECIFIC nucleotide is changed…. 5’-ATGCCCACCCAGGGGCCTCAGAAGAGGCTTCTGGGTTCTCTCAACTCCACCTCCACAGCC ACCCCTCACCTTGGACTGGCCACAAACCAGACAGGGCCTTGGTGCCTGCAGGTGTCTGTC CCGGATGGCCTCTTCCTCAGCCTGGGGCTGGTGAGTCTGGTGGAGAATGTGCTGGTCGTG ATAGCCATCACCAAAAACCGCAACCTGCACTCGCCCATGTATTCCTTCATCTGCTGTCTG GCCCTGTCTGACCTGATGGTGAGTATAAGCTTGGTGCTGGAGACGGCTATCATCCTGCTG CTGGAGGCAGGGGCCCTGGTGACCCGGGCCGCTTTGGTGCAACAGCTGGACAATGTCATT GACGTGCTCATCTGTGGCTCCATGGTGTCCAGTCTTTGCTTCCTTGGTGTCATTGCCATA GACCGCTACATCTCCATCTTCTATGCATTACGTTATCACAGCATTGTGACGCTGCCCCGG GCACGACGGGCCATCGTGGGCATCTGGGTGGCCAGCATCTTCTTCAGCACCCTCTTTATC ACCTACTACAACCACACAGCCGTCCTAATCTGCCTTGTCACTTTCTTTCTAGCCATGCTG GCCCTCATGGCAATTCTGTATGTCCACATGCTCACCCGAGCATACCAGCATGCTCAGGGG ATTGCCCAGCTCCAGAAGAGGCAGGGCTCCACCCGCCAAGGCTTCTGCCTTAAGGGTGCT GCCACCCTTACTATCATTCTGGGAATTTTCTTCCTGTGCTGGGGCCCCTTCTTCCTGCAT CTCACACTCATCGTCCTCTGCCCTCAGCACCCCACCTGCAGCTGCATCTTTAAGAACTTC AACCTCTACCTCGTTCTCATCATCTTCAGCTCCATCGTCGACCCCCTCATCTATGCTTTT CGGAGCCAGG AGCTCCGCATGACACTCAGGGAGGTGCTGCTGTGCTCCTGGTGA- 3’

mc1r Gene Sequence Let’s look at what happens when ONE SPECIFIC nucleotide is changed…. 5’-ATGCCCACCCAGGGGCCTCAGAAGAGGCTTCTGGGTTCTCTCAACTCCACCTCCACAGCC ACCCCTCACCTTGGACTGGCCACAAACCAGACAGGGCCTTGGTGCCTGCAGGTGTCTGTC CCGGATGGCCTCTTCCTCAGCCTGGGGCTGGTGAGTCTGGTGGAGAATGTGCTGGTCGTG ATAGCCATCACCAAAAACTGCAACCTGCACTCGCCCATGTATTCCTTCATCTGCTGTCTG GCCCTGTCTGACCTGATGGTGAGTATAAGCTTGGTGCTGGAGACGGCTATCATCCTGCTG CTGGAGGCAGGGGCCCTGGTGACCCGGGCCGCTTTGGTGCAACAGCTGGACAATGTCATT GACGTGCTCATCTGTGGCTCCATGGTGTCCAGTCTTTGCTTCCTTGGTGTCATTGCCATA GACCGCTACATCTCCATCTTCTATGCATTACGTTATCACAGCATTGTGACGCTGCCCCGG GCACGACGGGCCATCGTGGGCATCTGGGTGGCCAGCATCTTCTTCAGCACCCTCTTTATC ACCTACTACAACCACACAGCCGTCCTAATCTGCCTTGTCACTTTCTTTCTAGCCATGCTG GCCCTCATGGCAATTCTGTATGTCCACATGCTCACCCGAGCATACCAGCATGCTCAGGGG ATTGCCCAGCTCCAGAAGAGGCAGGGCTCCACCCGCCAAGGCTTCTGCCTTAAGGGTGCT GCCACCCTTACTATCATTCTGGGAATTTTCTTCCTGTGCTGGGGCCCCTTCTTCCTGCAT CTCACACTCATCGTCCTCTGCCCTCAGCACCCCACCTGCAGCTGCATCTTTAAGAACTTC AACCTCTACCTCGTTCTCATCATCTTCAGCTCCATCGTCGACCCCCTCATCTATGCTTTT CGGAGCCAGG AGCTCCGCATGACACTCAGGGAGGTGCTGCTGTGCTCCTGGTGA- 3’ The Cytosine at position 199 has now changed to a Thymine.

Consequence of Mutation
4.7 Consequence of Mutation The specific amino acid sequence is very important. One mutation within the sequence can have affect how the protein interacts with the melanocyte-stimulating hormone (α-MSH). This slide shows the structure of the MC1R protein situated across the cell membrane. The amino acid (#67) that changes is highlighted in red in the right hand panel. Amino Acid #67 = Arginine Amino Acid #67 = Cysteine

The Role of the MC1R Protein
4.9 The Role of the MC1R Protein When amino acid #67 is cysteine, the MC1R protein is unable to effectively bind the α-MSH. This changes the pigment pathway and eumelanin is not produced.

Plausible Mechanism; Observable Pattern
5.1 Plausible Mechanism; Observable Pattern In biological research, to say that something at the molecular or genetic level is responsible for a phenotypic trait, a plausible mechanism and an observable relationship should be identified. This slide sets up this material in this module. The “plausible mechanism” has been discussed (nucleotides, alleles, proteins, Eumelanin, etc.). The relationship, or pattern, will be described in the upcoming slides.

Mechanism: Alleles of mc1r Gene
5.2 Mechanism: Alleles of mc1r Gene The mc1r gene has two alleles: Allele R [Arginine at pos #67] Codes for a functional MC1R protein. Allele C [Cysteine at pos #67] Codes for a non-functional MC1R protein. We say it’s non-functional. Should we say that it is sub-functional? The genetic code for these two alleles differs by a single nucleotide substitution.

Observable Relationship: Genes vs. Fur Color
5.4 Observable Relationship: Genes vs. Fur Color There are three possible genotypes associated with the mc1r gene: The next few slides document a study done by Hoekstra et al, 2006. For more details see: This slide bridges the mechanism and the pattern. It shows hos different allele combinations tend to result in different eumelanin production abilities. Note – it is thought that the R and C allele do not demonstrate a simple dominant-recessive relationship; they are probably co-dominant on some level.

5.4 Observable Relationship: Genes vs. Fur Color There are three possible genotypes associated with the mc1r gene: RR  Arginine-Arginine: Indicates that both copies of chromosome 16 have an arginine amino acid at position #67 of the mc1r gene. + Eumelanin The next few slides document a study done by Hoekstra et al, 2006. For more details see: This slide bridges the mechanism and the pattern. It shows hos different allele combinations tend to result in different eumelanin production abilities. Note – it is thought that the R and C allele do not demonstrate a simple dominant-recessive relationship; they are probably co-dominant on some level.

5.4 Observable Relationship: Genes vs. Fur Color There are three possible genotypes associated with the mc1r gene: RR  Arginine-Arginine: Indicates that both copies of chromosome 16 have an arginine amino acid at position #67 of the mc1r gene. + Eumelanin CC Cysteine-Cysteine: Indicates that both copies of chromosome 16 have a cysteine amino acid at position #67 of the mc1r gene. - Eumelanin The next few slides document a study done by Hoekstra et al, 2006. For more details see: This slide bridges the mechanism and the pattern. It shows hos different allele combinations tend to result in different eumelanin production abilities. Note – it is thought that the R and C allele do not demonstrate a simple dominant-recessive relationship; they are probably co-dominant on some level.

5.4 Observable Relationship: Genes vs. Fur Color There are three possible genotypes associated with the mc1r gene: RR  Arginine-Arginine: Indicates that both copies of chromosome 16 have an arginine amino acid at position #67 of the mc1r gene. + Eumelanin CC Cysteine-Cysteine: Indicates that both copies of chromosome 16 have a cysteine amino acid at position #67 of the mc1r gene. - Eumelanin RC  Arginine-Cysteine: Indicates that one copy of chromosome 16 has an arginine amino acid on position #67 of the mc1r gene; the other copy has a cysteine in position #67 of the mc1r gene. ? Eumelanin The next few slides document a study done by Hoekstra et al, 2006. For more details see: This slide bridges the mechanism and the pattern. It shows hos different allele combinations tend to result in different eumelanin production abilities. Note – it is thought that the R and C allele do not demonstrate a simple dominant-recessive relationship; they are probably co-dominant on some level.

5.5 Observable Relationship: Genes vs. Fur Color Is there a relationship between the fur color of beach mouse individuals and the allele combinations (genotypes) they possess? CC homozygous = ? RR homozygous = ? RC heterozygous = ? This introduces a study done by Hoekstra and colleagues (2006). They looked at the different sub-species populations along the gulf coast and scored the coat colors amongst individuals. For each individual a score was given to the ear, rostrum, eyebrow, whisker, cheek, ankle and ventrum

House Mouse Karyotype (Mus musculus)
Chromosome 8 is approx. 130,000,000 bp

Observable Pattern: Color Scoring
5.6 Observable Pattern: Color Scoring Ear Rostrum Eyebrow Whiskers Cheek Ventrum Ankle

Observable Relationship: Scoring System
5.7 Observable Relationship: Scoring System 2 1 2 1 2 1 1 2 If one of the above body parts had dark fur it was given a score of “2”; very light or white fur “0”; intermediate fur, “1”. This slide demonstrates this for eight (hypothetical) mice for their cheek and rostrum. 1 2

Observable Pattern: Rostrum Color
5.8 Observable Pattern: Rostrum Color For rostrum color, across all populations, mice with an RR genotype had an average color score of 2 (all 126 individuals with the RR genotype had a “2” score). Mice with an RC genotype had an average rostrum color score of 1.81 (215 individuals had the RC genotype – of these, 175 were given a score of “2”, 40 were given a score of “1”). Mice with a CC genotype had an average rostrum color score of 0.81 (118 individuals had the CC genotype – of these, 27 were given a score of “2”, 42 were given a score of “1”, 49 were given a score of “0”). Mice with the genotype RR have the darkest rostrum color.

Observable Pattern: All Body Parts
Average Color Scores for: Body Part Rostrum Whisker Cheek Eyebrow Ear Ventrum Ankle RR Individuals 2.00 1.42 1.28 1.83 1.13 0.91 1.06 RC Individuals 1.81 1.00 1.25 1.54 0.80 0.55 0.82 CC Individuals 0.81 0.45 0.69 0.79 0.28 0.00 0.29 This slide shows the average color score for all 7 body parts among RR, RC and CC individuals. Two things should be evident from this slide. First, CC individuals tend to be lighter than RC individuals which tend to be lighter than RR individuals. Second, variance in genotype does not explain the entire pattern in mouse fur color. E.g: Why do RR individuals not have an average color score closer to 2? Why do CC individuals not have an average color score closer to 0? For more details see: Average 1.38 1.11 0.47 Hoekstra et al 2006

Average Color Scores for:
5.9b Average Color Scores for: Body Part Rostrum Whisker Cheek Eyebrow Ear Ventrum Ankle RR Individuals 2.00 1.42 1.28 1.83 1.13 0.91 1.06 RC Individuals 1.81 1.00 1.25 1.54 0.80 0.55 0.82 CC Individuals 0.81 0.45 0.69 0.79 0.28 0.00 0.29 Rather than explaining the results in the table shown in the previous you can ask your students to interpret the table – does it confirm or refute the likelihood of a genetic basis for fur color differences among mice? Average 1.38 1.11 0.47 Question: What does the above table tell you? Does it confirm or refute a genetic basis for differences in fur color among mice?

5.10 Questions: There is a clear pattern: beach mice with the RR genotype tend to be darker than those with the RC or CC genotype. Why is the average score for RR mice score less than 2 for most body parts? Why is the average score for CC mice greater than 0 for most body parts? RC mice are closer in fur color to RR mice than CC mice. Does this mean that R is dominant over C? Be prepared to explain your answer.

5.11 Question: Differences in fur color among beach mouse populations can be fully explained by the relative frequency of C and R alleles present within each population. Strongly Agree Agree Unsure/Confused Disagree Strongly Disagree This question is simply designed to check whether the students understand that the MC1R allele is one of the contributing factors towards fur color differences. Based on the table presented in slide 5.9 students should be able to articulate that MC1R is not the sole mechanism of fur color differences.

Predict Allele Frequencies

Actual Allele Frequencies
5.12b Actual Allele Frequencies 100% R 0% C 30% R 70% C 70% R 30% C 95% R 5% C 5% R 95% C 100% R 0% C

5.13 Fur color differences among beach mouse sub-species (i.e. populations) cannot be fully explained by differences in R:C allele frequencies. Why not?

In Class Exercise on Mouse Evolution
Scenario: Start with an ancestral, inland population in which all individuals have dark fur. The ancestral population evolves, resulting in one population that is still inland, and another that now lives on the beach. Present-day Inland Population Ancestral Inland Population Present-day Beach Population Time

In Class Exercise on Mouse Evolution: Questions for Student Teams to Consider
When did the ancestral population live? How big was it (number of individuals)? What were the mc1r genotype frequencies? The mc1r allele frequencies? How big is the present day inland population (number of individuals)? What are the mc1r genotype frequencies? The mc1r allele frequencies? How big is the present day beach population (number of individuals)? Where along the timeline did an R  C substitution in MC1R occur?

The Ecology of Fur Color in Beach Mice
2.0 The Ecology of Fur Color in Beach Mice ** Notes on the slides in this section: The following few slides are included as an overview of the ecology of this case study. For more information visit: Research indicates that the maintenance of different coat colors among subspecies/populations is achieved through top-down predation pressure from visual hunters.

Beach Mouse Food Facts:
2.1 Beach Mouse Food Facts: These slides show where P. polionotus fits into a (very general) food web. The main point here is that many (most) of its predators are “sight and sound” hunters.

Hunting Style of Predators
2.2 Hunting Style of Predators Sight and Sound Hunters Taste/Smell Hunter The majority of predators are sight and sound hunters. Therefore, if a mouse blends into its environment it may have a better chance of survival.

Predator-Prey Experiment (The Advantage of Fur Color)
2.3 Predator-Prey Experiment (The Advantage of Fur Color) This slide and the next correspond to a study done by Kaufman (1974) Adaptive coloration in Peromyscus polionotus: experimental selection by owls. Journal of Mammalogy 55: It can be found here: - In this study Kaufman tested the hunting behaviors of barn and screech owls. When light and dark mice were put in a light soil color enclosure, owls tended to catch the dark mouse first. When light and dark mice were put in a dark soil color enclosure, owls tended to catch the light mouse first.

Predator-Prey Experiment (The Advantage of Fur Color)
2.4 Predator-Prey Experiment (The Advantage of Fur Color) Owls catch dark mouse first 37% of the time Owls catch light mouse first 63% of the time. Owls catch dark mouse first 64% of the time Owls catch light mouse first 36% of the time.

Regional Pattern: Fur Color and Habitat Color
2.5 Regional Pattern: Fur Color and Habitat Color Researchers examined fur color in nine beach mouse populations. Fur color brightness was significantly correlated to soil brightness where each population lived. This is an experiment by Belk and Smith They show that there is a very strong correlation among average fur brightness and soil brightness for nine subspecies (i.e. populations) of P. polionotus. [Brightness is defined as the total intensity of light reaching the measuring instrument at a standard distance.] The study can be found here: Side note: the study by Belk and Smith concluded that selective-predation on non-camouflage mice was probably not the driving mechanism of mouse coat color amongst P. polionotus. However, the authors took objective measures of mouse camouflage taking into account the entire wavelength spectrum of light. However, the vision of many P. polionotus predators (like owls) is not truly trichromatic, as Belk and Smith’s test assumes. Rather, their eyes likely have increased rod cells densities that allows for better night vision. Because of this discrepancy we have left out the camouflage (“crypsis”) analysis they detail in their paper.

Predation Study – Clay Mice
2.6 Predation Study – Clay Mice This is the key figure from a predation study conducted in 2010 by Vignieri et al: Light clay mice placed on dark soil were attacked more frequently than dark clay mice on dark soil. Conversely, dark clay mice placed on light sand were attacked more frequently than light clay mice on light sand. (A) Two locations with different color soil where predation on clay mice was tested. (B) Most attacks in light soil environments were on dark mice; most attacks in dark soil environments were on light mice.

2.6b Attack on a Clay Mouse This is a picture of a clay-mouse that was attacked. Picture credit to Hoekstra.

2.7 Summary Evidence suggests that fur color may have evolved as a result of selective predation. Fur coloration matching the habitat coloration leads to less detection by predators and increases the odds of successful reproduction.

Clicker Q1 The C  T substitution at position 199 of the mc1r gene:
6.6 Clicker Q1 The C  T substitution at position 199 of the mc1r gene: arose by a mutation in the beach mouse populations in response to a need for protection from predation. leads to the failure of melanocytes to make an MC1R protein. arose by a mutation then increased in frequency because it was selectively advantageous in the beach mouse populations. had no effect on the beach mouse populations. produced an alternate allele that was detrimental to mice on the white sand beaches

6.7 Clicker Q2 What was the reason for the lighter coat colors of the mice on the white sand beaches? Owls and other carnivores prey on beach mice that do not carry the mutant allele. A substitution of cysteine for arginine at position 67 of the MC1R protein. A substitution of thymine for cytosine at position 199 of the mc1r gene nucleotide sequence. The failure of melanocytes to lay down melanin pigment in the cortex of hairs of the lighter colored beach mice. The poorer binding affinity for α-MSH and the lower amount of cAMP produced by individuals with the mutated MC1R protein. - Proximate vs. ultimate causation. In different ways all of these are correct. This question can provide a good basis for debate amongst students.

The Case of Fur Color Evolution in Beach Mice or

Similar presentations

Presentation on theme: "The Case of Fur Color Evolution in Beach Mice or"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

The Case of Fur Color Evolution in Beach Mice or

Similar presentations

Presentation on theme: "The Case of Fur Color Evolution in Beach Mice or"— Presentation transcript:

Similar presentations

About project

Feedback