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Homo litoreus Seashore Man Part one In a nutshell.

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Presentation on theme: "Homo litoreus Seashore Man Part one In a nutshell."— Presentation transcript:

1 Homo litoreus Seashore Man Part one In a nutshell

2 How it happened Wetland and shoreline dwelling ancestral groups, omnivorous. Not specifically adapted, omnipotent. Stage 1.

3 Rising and falling sealevels Some small groups were trapped on isolated archipelagos. Living as beachcombers then was obligatory to survive. Swimming and diving AND upright wading with stronger legs. Using hands to grab mollusks and crustaceans (fruits de mer). Controlled breathing stimulating vocalization. Losing fur to prevent hypothermia (wet T-shirt effect), developing subcutaneous fat for insulation in water and a rapid reacting subcutaneous capillary system to overcome overheating on land(blushing) and underheating in water (pale). Stage 2.

4 Eventually man started his walkabout Sealevels falling: Freed from the isolated archipelago mans ancesters spread rapidly along riverbeds and coastlines. Walking, swimming, rafting and exploring inlands. Getting better in walking, tool handling, killing and singing; still fond of water and salt... His xenophobic nature guaranteed a very rapid dispersion. Stage 3.

5

6 The whole possible story

7 HOW? Part two Part two What adaptive forces could lead to the specific human traits he has today? What adaptive forces could lead to the specific human traits he has today? The starting point in this vision are NOT fossilized and fragmented remains. The starting point in this vision are NOT fossilized and fragmented remains. Our bodies and our habits of today do give us the obvious clues... Our bodies and our habits of today do give us the obvious clues...

8 The interglacial island hypothesis This is the proposed repetitive bottleneck responsible for the adaptational mix of human features. Richard Little, Glacial Research Society, 2005

9 Matching with outbursts of new pre human forms Richard Little, Glacial Research Society, 2005

10 Homo litoreus Seashore Man Theory of shedding a fur on dry savannah tested: a kitchen table experiment

11 What was the habitat where human ancestors became bipedal and naked? The general opinion is: on the African savannah Man started being bipedal Man started being bipedal Shed his fur to overcome excess heating while hunting Shed his fur to overcome excess heating while hunting Vertical position reduced radiated surface. Vertical position reduced radiated surface. Was able to spot possible dangers and prey in a better way Was able to spot possible dangers and prey in a better way Freed hands enabling the use of tools Freed hands enabling the use of tools

12 Australopithecus The common picture.... But what about the lagging woman: doest she seem in trouble...?

13 Paleoanthropologists This picture is drawn by paleoanthropologists. This picture is drawn by paleoanthropologists. Is it biologically convincing? Is it biologically convincing? Are other suggestions plausible?? Are other suggestions plausible?? Oldest fossil remains of hominoids are all bipedal; no partly knuckle walkers are found. Oldest fossil remains of hominoids are all bipedal; no partly knuckle walkers are found. If it is the result of strong selective forces on a small isolated group, fossils are scarce If it is the result of strong selective forces on a small isolated group, fossils are scarce A growing minority is tinkering with an other possibility … A growing minority is tinkering with an other possibility …

14 Homo litoreus is a more proper name than Aquatic Ape In the sixties of the last century marine biologist sir Alistair Hardy suggested a more aquatic stage in human evolution. The Aquatic Ape Theory was born (A.A.T.) suggested a more aquatic stage in human evolution. The Aquatic Ape Theory was born (A.A.T.) Wading asks for stronger legs and could have lead to bipedality.. Wading asks for stronger legs and could have lead to bipedality.. A wet fur results in strong cooling by frequently entering and leaving the water (the wet T-shirt effect) A wet fur results in strong cooling by frequently entering and leaving the water (the wet T-shirt effect) Shedding fur and storing subcutaneous fat is an obvious solution Shedding fur and storing subcutaneous fat is an obvious solution Controlled blood circulation in the outer skin guarantees cooling (radiator effect); overall transpiration adds to this Controlled blood circulation in the outer skin guarantees cooling (radiator effect); overall transpiration adds to this Man has a more than average diving reflex and controllable breathing Man has a more than average diving reflex and controllable breathing His newborns are clearly water adapted His newborns are clearly water adapted

15 Fur, subcutaneous fat or neither? There are no hunting animals without fur on the savannas. There are no hunting animals without fur on the savannas. They do all transpire, but far less than humans They do all transpire, but far less than humans They have a more controllable water balance, no subcutaneous fat and no dense network of blood vessels in their skin They have a more controllable water balance, no subcutaneous fat and no dense network of blood vessels in their skin They are all faster runners than man, with no hyperthermia They are all faster runners than man, with no hyperthermia Cheetah Cheetah

16 A ridiculous proposal By P. wheeler, John Moore University Liverpool.

17 The fur argument on the test… Hypothesis 1: subcutaneous fat reduces heat loss in water and is a disadvantage on land, leading to overheating. Hypothesis 1: subcutaneous fat reduces heat loss in water and is a disadvantage on land, leading to overheating. 2: A wet fur leads to strong cooling as result of heat loss to evaporation 2: A wet fur leads to strong cooling as result of heat loss to evaporation 3. A dry fur insulates on land, from the heat as well as from the cold 3. A dry fur insulates on land, from the heat as well as from the cold

18 How it is done A kitchen table experiment

19 Equipment needed: 3 1,5 liter PET bottles 3 1,5 liter PET bottles 150 grams of Vaseline 150 grams of Vaseline A woolen sock A woolen sock 3 Temperature sensors 3 Temperature sensors A ventilator A ventilator Warm and cold water Warm and cold water

20 Subcutaneous fat 1,5 litre bottle greased with 150 grams of Vaseline = subcutaneous fat: equals 10% of body mass, just as in man; 1,5 litre bottle greased with 150 grams of Vaseline = subcutaneous fat: equals 10% of body mass, just as in man; Plastic foil as skin Plastic foil as skin 40° C water 40° C water

21 1 blank, 1 fat and 1 sock

22 Measuring equipment In the blank; a thermometer In in the other two a thermal sensor

23 Submerged in cold running water

24 Measuring in air

25 Results in water SEASHORE MAN HYPOTHESIS Time min blankfurfat temperature waterStarting value in bottles ,52225,5 2516, ,521

26 Fat Fur Blank

27 Conclusions for water If the temperature after 15 minutes cooling for the blank is 100%, then this is reached 11,3% later with fur; fat is 16,7% slower If the temperature after 15 minutes cooling for the blank is 100%, then this is reached 11,3% later with fur; fat is 16,7% slower The hypothesis seems correct The hypothesis seems correct More tests are needed to be sure: repeated by 40 students it showed same trend More tests are needed to be sure: repeated by 40 students it showed same trend NB: even in tropical conditions, coastal waters have a lower temperature than the body core. Heat loss due to happens anyway: an adaptation is obligatory. NB: even in tropical conditions, coastal waters have a lower temperature than the body core. Heat loss due to happens anyway: an adaptation is obligatory.

28 Results in air Min. blankfurfatOutside temparature18,5 044 Water temperature ,242, ,540Total cooling Blank16,5 1435,53437 Total cooling Fur Total cooling Fat 13,5 2530,528,532,5 3028,526,330,5

29 fat blank fur... Fat Fur Blank

30 Conclusions for air Cooling with a wet fur is the strongest. Fat cools the slowest. If the cooling after 15 minutes is 100%, fur reaches it 7,5% earlier and fat 12,5% later. Fur and fat differ 20% Cooling with a wet fur is the strongest. Fat cools the slowest. If the cooling after 15 minutes is 100%, fur reaches it 7,5% earlier and fat 12,5% later. Fur and fat differ 20% It seems to proof the disadvantage of a wet fur and the advantage of subcutaneous fat for an in- and -out of the water lifestyle It seems to proof the disadvantage of a wet fur and the advantage of subcutaneous fat for an in- and -out of the water lifestyle But at the same time it shows the possible handicap of overheating under dry, sunny conditions But at the same time it shows the possible handicap of overheating under dry, sunny conditions Total body transpiration and a controllable heat radiating blood stream in the skin are obvious adaptations to this problem

31 Adapted to the savanna? This simple kitchen table experiment shows: Man on the hot savannah would lose much water on evaporation to keep him cool. Man on the hot savannah would lose much water on evaporation to keep him cool. He would be better off keeping an insulating fur against sunburn and overheating. He would be better off keeping an insulating fur against sunburn and overheating. In a water bound habitat his specific adaptations subcutaneous fat and a controllable bloodstream in the skin are more appropriate.

32 Sea Gypsies

33 Swimming pool Europe

34 The diving reflex Man shows a moderate diving reflex; research by dr. Erica Schagatay showed an average slowing down of the heartbeat by 15 beats per minute. Students of the Zuyderzee College in the Netherlands repeated her measurements in the lab and in the swimming pool, assisted by local scuba divers.

35 Kitchentable version Kitchentable version The principle..

36 In the lab Cold water

37 In the lab Measuring the heart beat lying down and face submerged in cold water

38 In the swimmingpool Submerged 4m, assisted by scuba divers from diving club De Zeewolf, Emmeloord

39 results Heartbeats per minute standing Laying down Face submerged m submerged highestlowestmean

40 graph Standing laying down face submerged 4m deep

41 Probability For laying down and laying down with submerged face the T value for coincidental difference is 16/(283,5/30) = 16/3,07=5,3746 For laying down and laying down with submerged face the T value for coincidental difference is 16/(283,5/30) = 16/3,07=5,3746 P < 0,001 P < 0,001

42 Our start….

43 Adaptations in newborns They hold their breath when submerged They hold their breath when submerged Can swim under water Can swim under water Turn on their back with an eskimo roll of their legs; pop up like wearing a life jacket with free airways Turn on their back with an eskimo roll of their legs; pop up like wearing a life jacket with free airways Are born with a thick protective layer of sebum, like some species of seals Are born with a thick protective layer of sebum, like some species of seals Floating and swimming abilities precede walking and crawling

44 It is demonstrated in this film on drowning prevention for toddlers. Source: Youtube babies do it spontanuously, it can be reinforced by training. No swimming in earley infancy means missing the time frame for imprinting.Older children have to start anew.

45 Trained toddler Source: Youtube

46 Sebum Skin fat or sebum is secreted by subcutaneous glands. Skin fat or sebum is secreted by subcutaneous glands. The thin, waxy layer is water repellant, contains an infection blocking biofilm of skin bacteria and has UV filtering properties. The thin, waxy layer is water repellant, contains an infection blocking biofilm of skin bacteria and has UV filtering properties. This also can be interpreted as a waterbound adaptation. This also can be interpreted as a waterbound adaptation.

47 Sebum ABSTRACT Br J Dermatol Dec;103(6): Sebum levels during the first year of life. Agache P, Blanc D, Barrand C, Laurent R. Skin surface lipid levels in forty-five newborn babies and 193 infants aged less than 12 months were determined by an optical density method, using samples collected on ground glass. Although there was a wide individual range, sebum levels in the first week of life were very high, and were of the same magnitude as in adults. Females displayed a different pattern of sebum excretion from males. On the first day of life, the levels in females were lower than in the males but a large increase took place between the 3rd and 6th day, followed by a fall, bringing the level below that of the males. At 6 months the levels were low in both sexes. These findings suggest that there is a strong stimulation of sebum secretion before birth which probably stops at or soon after birth. Androgen may be involved in this stimulation and the probable role of dehydroepiandrosterone (DHEA) is discussed.

48 Colofon D. Meijers MSc biology & general sciences, cartoonist D. Meijers MSc biology & general sciences, cartoonist George Weber George Weber Urchin Rock underwater photography Urchin Rock underwater photography 11/sea_change.html /sea_change.html /sea_change.html /sea_change.html 2007


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