Evolution Flashcards
What is adaptation?
it is a structure, behaviour or physiological process that helps an organism survive and reproduce in a particular environment. Example: camouflage, hibernation, needle-sharp talons and excellent vision of an owl, white fur and webbed, flat feet of polar bears.
What is mimicry?
A structural adaptation in which a harmful species resembles a harmless species in coloration or structure. Predators that avoid the harmful species will also avoid the mimic. For example, the viceroy butterfly is palatable to the predators but the monarch is not (monarch is poisonous), so predator’s avoid both because they don’t want to get sick.
~type of beetle that look,s like a type of ant and has the same pheromone and gains access to the queen and kills her, then the rest of the beetles come and eat everyone
~scarlet Kingsnake mimics colours of poisonous coral snake
What is variation?
differences between individuals, which may be structural, functional, or physiological
What is mutation?
a permanent change in the genetic material of an organism; the only source of new genetic variation
What are mutagens?
are environmental agents that can also cause mutations in DNA. i.e. ultraviolet radiation, x-ray radiation, toxic chemicals, nuclear energy
What are mutations in Gametic Cells?
~if the mutation occurs in a somatic cell, the mutation disappears from the population when the organism dies
~if the mutation alters the DNA in the gamete, the mutation may be passed on to succeeding generations as a new allele
What is selective advantage?
a genetic advantage that improves an organism’s chance of survival, usually in a changing environment
Ex. the water flea Daphnia, normally lives in water that is around 20 degrees Celsius and it cannot survive in water 27 degrees Celsius `or warmer, but a mutation allows some to survive in temperatures between 25 degrees Celsius and 30 degrees Celsius allowing them to reproduce and survive when temperatures are high
What is antibiotic resistant bacteria?
-antibiotics are drugs used to treat infections. When they reproduce asexually (in under 30 minutes in favourable conditions). It allows mutations to occur. When you have all these bacteria inside you and you’re treated with antibiotics. It will kill all the bacteria, except for the ones with a mutation that makes it resistant. The antibiotics essentially “choose” the resistant strain, allowing them to reproduce and create many resistant bacteria making it harder to treat.
What is natural selection?
the process by which characteristics of a population change over many generations as organisms with heritable traits survive and reproduce, passing their traits to offsprings
What is selective pressure?
environmental conditions that select for certain characteristics of individuals and select against other characteristics
What is selective advantage?
A genetic advantage that improves an organisms chance of survival, usually in a changing environment
What is fitness?
The relative contribution an individual makes to the next generation by producing offspring that will survive long enough to reproduce
What is artificial selection?
Selective pressure exerted by humans on populations in order to improve or modify particular desirable traits
~example: cows bred to produce more milk, chickens bred to grow large number of eggs, some chickens are bred to grow rapidly and have large muscles for increased amounts of meat; rice, corn, meat, vegetables, bred crops to be drought- or pest-resistant
What is a mono culture?
extensive plantings of the same varieties of species over large expanses of land.
~the big risk for monoculture is that since everything is so similar, if a new disease infests the crop population, most of the individual plants will be affected in the same way and the whole population could be killed or severely damaged
What are gene banks?
Contain populations of early ancestors of modern plants.
~our most important food plants came from wild ancestors with genetic combinations that allowed them to survive and reproduce in their environment