Human Evolution - Biodiversity
What is a species
2 organism that are able to produce a fertile offspring are the same species
What is the primate order
Lemurs, Tarsiers, Monkes and apes there are 204 species
The antropoids are split to new world monkey, old world monkey and hominoids
These are unique due to have fully opposable thumbs that toch all the finger for grasping things
How have primates evolved
Ancestor may have been small isectivores like tree shrews or flying lemurs and have evolved to have hands and feet that can grasp things
They have a relative large brain and forward facing eyes
Omnivorous diet
What species are the Hominoids
These are Gibbons, Goriallas, Humans, orgunatans and Chimps
They all lack a tail
What was the first hominoid
Proconsul, Kenyapithecus, Moropithecus and Equatorius all may have been the first hominoid but cant tell for sure due no tails preserved in fossil record
They were all found in east africa - Kenya, Ethiopea and Tanzania
What are the Hominids
These are all the species that are more closely related to humans than to chimps
These have larger braisn than chimps as human have 3x brain volume than chimps
They are bipedal so walk on hind legs due to cooling of global temperature so lower forest volume and more savannah in africa so lead to evolution of this
What are the extinct group that lead to homo sapines
There was not linear evolution but more an evoltuon net and species cross over that then lead to eventually H.Sapien formation
Ardipithecus
These are from 4.4 mya
1.2 M tall and brain size of 300-400 cm3
Had upright posture so our anscestors didnt look like chimps
Australopitehcus
Lived 4-2.5 mya
Brain size of 400-500 cm3 and 1.2-1.4 m tall
Fully bipedal due to fossil record and also preserved footsteps
Paranthropus
Lived 2.5 mya
1.3-1.5m tall
Stronh heavy bone and muscle and a brain size of 550cm3
What are Homo habilis
HOMO genus due to larger brain size, flatter face, weaker jaws and smaller mouth
2.5 mya and brain size of 600-700cm3
First evidence of tool making so had large enough intelligence to do this
Later form called H.eragster had brain of 900cm3
What are Homo erectus
Around 2 mya
Brain size of 1100-1200 cm3
Linear descendence from H.habilis or Eragster
First hominoid to leave africa and move to Asia or Europe
Homo Neanderthals
In europe from 350,000-200,000 years ago
Descended from H.erectus in europe
Heavy and muscular
Brain size of 1500-1600 cm3
Not out anscestor
How did H.sapien evolve
Multiregional model= Only 1 wave of migration from africa of H.erectus thsat migrated from europe and asia then there was gene flow to get 3 lineages that then enveloped to 1 H.sapien
Out of Africa Model= H,erectus kleft africa migrated to asia and europe, and then another migration wave of more developed Homo then get gene tranfer and larger gene pool so get H.sapien
What are Big brains
They are metabolically expensive with 18% energy budget
Can force premature birth due to large head
Increase survival via social skills and mammals and H.,sapine have the largest heads over other animal groups
What is culturla evolution
Cultural knowledge passed between generations in not a gene but what is called a meme
Art,Music, Science ect
What did Darwin publish
In 1859 a year after he was in the Galapagos island he wrote the species of life book that showed how natural selection and what it caused
What were the pre Darwin ideas of evolution
Lamark the french philospher thought all animals linked together and never went extinct but got more complex to make new animals
What did Darwin and Lamark agree on
Earth is old, Heritability is necassary and envionment will go through phase
What did Darwin and Lamark disagree on
Darwin thought environment alter ability to survive as the ebst suited have the greater fecundity so more likely to survive and less fecund species go extinct in the environment
Lamark thought environment alter organism behavior and can cuase organ change to get smaller or bigger
Organism evolve linear and progressive so no extinction
What are Darwin idea of Heritability
Paternal charcterists are passed from both mum and dad
Some traits= You can or you dont get but is luck depending on genes passed down so recessive or dominant genes
Most traits = You get some of it so tall people have tall kids
Darwin idea of natural selection
Immense competition to survive in natural world
For a population to stay the same each adult need to produce 1 young that survives and reproduce but many dont so any advantage gained will increase survival so more likely to reproduce
Darwin idea of geological time
Combined geological time, fossil record and empirical observation he formulated idea of natural selection over millions of years
It is important due to:- It is rare event a mutation and evolution due to DNA mutation chance is very low as in 3 billion BP only 30 mutate