3. 2. 1 - Evolution and adaptation Flashcards
what did charles darwin suggest?
that evolution occurred due to natural selection
- it gives a scientific explanation for the great diversity of life on earth and for all organisms that have existed and become extinct
how did charles darwin come to this conclusion?
when he was travelling the world, he noticed that the organisms he saw were adapted to their particular environment
what were the main ideas that charles darwin put forward?
- living organisms that reproduce sexually show great variety in their appearance
- organisms produce an excess of offspring (many offspring do not survive to reproduce themselves) –> always a struggle - competition between the members of the same species
- organisms that inherit characteristics that give them an advantage are most likely to survive and pass on the desired feature to their offspring
- organisms that inherit characteristics that put them at a disadvantage will be more likely to die out before they can reproduce
what is natural selection?
the process by which the organisms that are best adapted in a particular environment are most likely to survive and reproduce, passing on their advantageous alleles to their offspring.
what is evolution?
a change in the genetic composition of a population of organisms over several generations, as a result of natural selection acting upon variation
- bringing about adaptations and in some cases leading to the development of a new species
define ecology
the study of the interactions of organisms with each other and with the environment in which they live
define niche
the role of an organism within the habitat in which it lives
what is neo-darwinism?
the modernised statement of the theory of evolution:
- evolution of organisms occurs as a result of different genotypes leading to different phenotypes within a specific environment
- those alleles that deliver the adaptations best suited to the environment are most likely to be passed on to the next generation
what are the different kinds of successful adaptations?
- anatomical
- physiological
- behavioural
what are genotypes?
the genetic make-up of an organism with respect to a particular feature
what are phenotypes?
the physical traits (including biochemical characteristics) expressed as a result of the interactions of the genotype with the environment
what are alleles?
versions of a gene, a variant
what are anatomical adaptations?
adaptation that involves the form and structure of an organism
what are physiological adaptations?
an adaptation involving the way the body of the organism works
- including differences in the biochemical pathways or enzymes
- e.g: mammalian diving response
what are behavioural adaptations?
an adaptation involving programmed or instinctive behaviour making organisms better adapted for survival
- e.g: huddling together for warmth –> improves survival chances of both individuals and a group of organisms
