Natural Selection Flashcards
(26 cards)
how many islands in the Galapagos
19
where are the Galapagos islands located
Pacific Ocean
features of natural selection
variation in a population
selection pressure
environment
adaptations
natural selection
the process in which an environmental factor acts on a population and results in some organisms having more offspring that survive to reproduce than others
over production
species tend to produce more offspring than can survive to maturity
variation
there is a natural variation between individuals in a population
selection
-survival of the fittest
some individuals are better suited to their environment than others and so survive better
reproduction
individuals that survive better are able to reproduce more during their lifetimes, and pass on their characteristics to the next generation
adaptation
over many generations, the characteristics of individuals that survive better and produce more, become more common in the population.
evolution
any change to the heritable traits in the population across generations
two reasons for changes in heritable traits
- mutations
- two individuals reproduce
two examples of evolution
- peppered moth changing colour because of soot
- dogs originating from grey wolves
who is Charles Darwin and Alfred Russell walace?
they are two scientists who studied and attempted to explain the process of evolution
what is comparative anatomy
the study of differences and similarities between living things
what are the two claims made for evolution
- all living things on earth are related as they evolved from a common ancestor
- evolution is powered by natural processes
embryology
the study of how creatures develop before being born or hatching from an egg
-developing in the womb
fossil record
used to see the similarities in the bones from organisms millions of years ago. they help the scientists to understand where the creature evolved from.
dna comparison
dna molecules contain chemical codes which act like recipes for living things. dna researchers can compare the dna of different living creatures to find out who are the most closely related
how many species are alive today
over 8.7 million
independent lines of evidence
comparative anatomy embryology and development fossil record dna comparison species distribution evolution observed predictive power of evolution nested hierarchies of traits
what animals do cetaceans include
whales, dolphins and porpoises
selection pressure
the effect of the selective agent on a population
selective agent
an environmental factor that acts on a population during natural selection
Isolation
Keeping interbreeding groups apart by some barrier or mechanism
