What makes humans unique?
- language
- bipedal
- large brain
- precision grip - opposable thumb
- consciousness
- reason
- tool use
- agriculture
- non-reproductive sex - constantly in heat
- evolve culturally
- super-cooperators
opposable thumbs
- allows grasping
- only humans can oppose the tip of the thumb and the tips of all the fingers
- most primates have them
language
- open-ended and finite
- other animals - closed systems with finite possibilities
consciousness
- sentience or awareness and external existence
- other animals - basic self-awareness
bipedalism
- walking on 2 legs costs more energy than 4
- running on 2 legs is more efficient than 4
- other bipedal animals - kangaroos, birds, dinosaurs
naked ape
- only naked great ape and primate
- appear naked - same density of body hair as other apes of our size (fine and colourless - peach fuzz)
- other naked mammals = elephants, rhinos, hippos - constant risk of overheating
animal with the largest brain
blue whale - 8kg
human brain
- large brain for our body size
- 4x larger than chimps
largest brain amongst hominids (great apes)
neanderthals
what % of animals use tools?
1 %
Why are Darwin and Wallace so famous?
they provided a plausible mechanism for evolution
who invented the theory of evolution
Lamarck - full theory of evolution 50 years before Dawrin and Wallace
- lacked plausible mechanism
Define evolution
changes in the genetic composition of a population over time
Explain the Darwin/Wallace theory
- organisms within species vary in traits
- some of this variation is due to genes
- populations have the capacity to over-reproduce
- inference 1 - some survive to reproduce, some don’t
- inference 2 - those with higher reproductive success leave more offspring and copies of their genes
- evolution is a logical and empirical fact
structure of a Darwinian argument
- giraffes vary in neck length
- some of this variation is due to genes.
- hypothesis = giraffes with longer necks can reach food that is unavailable to others
- giraffes with longer necks survive better and leave more offspring than those with shorter necks
- over generations, the genes for long necks increase in the population
How many great apes are there?
- Humans
- Chimpanzees
- Bonobos
- Gorillas
- Orangutangs
- Tapanuli Orangutangs
How many species of primates are there?
250
How many species of mammals are there?
5000
how many species of vertebrates are there?
50,000
how many species of animals are there?
1 million
how many species are on earth?
10 million
how many cells are in the human body?
30 trillion
how many chromosomes do other great apes have?
24 pairs - gorillas, chimps, bonobos.
our chromosome #2 - fusion of 2 chimp chromosomes (2A and 2B)
how many chromosomes do humans have?
23 chromosomes
22 pairs - autosomal
1 pair - sex chromosomes
