7. Evolution Flashcards
(28 cards)
Why is natural selection important?
Our environment cannot support unlimited population growth
What is evolution?
Survival of the fittest
What is an example of fast evolution?
Resistance to antibiotics- can take 6 months
What is a example of slow evolution?
The coelacanth has stayed the same for 150 million years
What are selective presssures?
Environmental factors that increase of decrease the likelihood that a particular combination of genes make it to the next generation
Do adaptive genes always need to be the best?
No- they just have to be better than those in the same environment as us
e.g. just have to be faster than the person next to us
What is natural design for gene replication?
We are a constellation of genes that drive behaviour- evolution does not operate on individuals but genes that need to make it to the next generation
What is superabundance?
Animals and plants produce more offspring than necessary
What is natural variation?
Each offspring has some level of genetic variation
What are some examples of selection pressures?
Predation, susceptability to disease and toxins
What is an evolutionary trade-off?
Organsims cannot invest in everything so they choose whether to invest in one trait of another
What is intersexual competition?
Attributes that females and males use to select mates
What in intrasexual competiton?
Occurs within a sex for access to a mate
What is a social/group selection pressure?
Organisms who are better able to get along with groups have greater chances to reproduce
What is the environment of evolutionary adaptiveness?
We are best suited to the environment we last evolved to, millions of years ago
What are spandrels?
Non-adaptive evolutionary by products e.g. belly buttons
What are vestigial features?
Structures which have lost their function due to evolution
What are exaptations?
Evolved to serve one function and later used for another
Why are human brains wrinkled?
So we can fit more in our skull
Why can humans compete with other species?
agile hands, bipedalism, fire mastery, linguistic ability
Do more neurons increase brain size?
No- primate brains have adapted to gain neurons without the average neuron becoming larger which is more economical
How can humans supply all the energy to the neurons without eating so much?
We have genes that slow down the process of development allowing more time for growth
What’s neoteny?
Slowing the brain development process, allowing more time for growth
What is apprenticeship in evolution?
Youngling’s are guranteed to be exposed to adults they can learn from
