BIO 111: Foundations of Biology Unity and Diversity https://parupuntenobu.hatenablog.jp/entry/brain-active-neuron https://www.frontiersin.org/files/Articles/189737/fmicb-07-01689-HTML/image_m/fmicb-07-01689-g005.jpg https://www.google.com/search?rlz=1C1GGRV_enUS778US778&biw=1920&bih=943&tbm=isch&sa=1&ei=935xW4mEDuGFggeN0K64Aw&q=biodiversity&oq=biodiversity&gs_l=img.1.0.0l10.6215.6215.0.7948.1.1.0.0.0.0.71.71.1.1.0....0...1c.1.64.img..0.1.70....0.-lfOWOM788Q#imgrc=cEHq8SEn9KpOPM:

Unity

A. Made of the same stuff: Biomolecules in water Unity A. Made of the same stuff: Biomolecules in water https://byjus.com/biology/biomolecules/

A. Made of the same stuff: Biomolecules in water Unity A. Made of the same stuff: Biomolecules in water B. The molecules are organized into the same units: cells Why are cells small? https://www.philpoteducation.com/mod/book/view.php?id=777&chapterid=1027#/

Why such extraordinary similarity? Unity A. Made of the same stuff: Biomolecules in water B. The molecules are organized into the same units: cells C. The cells work in largely the same ways: energy conversion through ATP protein synthesis by reading DNA replication by division O.R.R.G.E.E. https://www.medicalsciencenavigator.com/physiology-of-self-renewal/ Why such extraordinary similarity?

Unity II. Diversity Bacteria

Unity II. Diversity Bacteria Archaea https://www.ck12.org/biology/archaea/lesson/Introduction-to-Archaea-Advanced-BIO-ADV/

Unity II. Diversity Bacteria Archaea Eukarya

Why such extraordinary similarity? Why such extraordinary diversity? Unity II. Diversity Bacteria Archaea Eukarya Why such extraordinary similarity? Why such extraordinary diversity?

Why such extraordinary similarity? - Divergence from Common Ancestors Unity II. Diversity III. Evolution Why such extraordinary similarity? - Divergence from Common Ancestors Why such extraordinary diversity? - Genetic Variation and Natural Selection

Unity II. Diversity III. Evolution The unity allows us to explain the diversity: all organisms have inherited DNA from their ancestors. The more similar the DNA, the less time has elapsed for mutational differences to accumulate (and the more recent their common ancestry). https://en.wikipedia.org/wiki/Phylogenetic_tree

Unity II. Diversity III. Evolution The unity allows us to explain the diversity: all organisms have inherited DNA from their ancestors. The more similar the DNA, the less time has elapsed for mutational differences to accumulate (and the more recent their common ancestry). We can use the number of genetic differences between species to estimate the amount of time that they have been diverging (molecular clock).

Another independent source of evidence regarding evolution: the fossil record

Earth History Life’s Diversity 1.8 bya: first eukaryote 0.7 bya: first animals 0.5 bya: Cambrian 0.25 bya: Mesozoic 0.065 bya: Cenozoic 4.6 bya: Earth Forms 4.0 bya: Oldest Rocks 3.8 bya: Oldest Fossils 2.3-2.0 bya: O2 increase

Thousands of Genera Millions of Years Ago All genera “well described” genera The “big five” Mass Extinction Events Thousands of Genera Millions of Years Ago http://en.wikipedia.org/wiki/File:Phanerozoic_biodiversity_blank_01.png

Another independent source of evidence regarding evolution: the fossil record

Unity II. Diversity III. Evolution Here is the ‘tree’ based on genetic similarity among existing species and the ‘hypothesis’ of common ancestry. We can use transitional fossils to test this hypothesis. Only evolution predicts that a transitional fossil, which is a third, different species from the descendants, should have existed at a time predicted by the genetic similarity of their descendants. (If they are unrelated and genetic similarity is NOT a function of common ancestry, then these ‘transitional species’ are just weird, goofy species; not the common ancestors. And they could thus have lived at any time in the past – not just where evolution predicts.

Unity II. Diversity III. Evolution Fossils of transitional forms are consistent with these genetic predictions. Tiktaalik – 375 mya Archaeopterix – 150 mya Australopithecus – 4.5 mya

Unity II. Diversity Evolution The Functional Significance of Diversity

The Functional Significance of Diversity A. Cellular Level Unity II. Diversity Evolution The Functional Significance of Diversity A. Cellular Level What is the effect of cellular diversity? How do these differences arise? https://www.quora.com/What-is-the-purpose-of-cell-diversity

Genetic Differentiation

Unity II. Diversity Evolution The Functional Significance of Diversity A. Cellular Level B. Ecological level What is the effect of species diversity? How do these differences arise?

All biological systems are complex assemblages of structurally and functionally different subunits. This DIVERSITY increases functional ability and efficiency (division of labor) Ultimately, as the system evolves this complexity, it becomes more and more dependent on that diversity to function: How well do human cells do with poorly functioning mitochondria? How well does a human do with poorly functioning red blood cells? How well does a population do with no reproductive adults? How well does an ecosystem do with no predators? System Components Organelle different molecules Cell different organelles Organ different cell types Organism different organs Population different organisms Community different species Ecosystem producers, heterotrophs, decomposers