Human Biology 2nd half Flashcards
What is evolution
Genetic changes in population over a very long time
What is population
The same species living together
What are some drivers of evolution
Variation in gene pools, mutations, sexual reproduction or natural selection
Describe two drivers of evolution
Sexual reproduction, two parents providing genetic information producing genetically different offspring. Natural selection, only the organisms best suited to survive and pass on genes are able to
What is biodiversity
The variety of living things
What are species diversity
Range of species in an ecosystem
Genetic diversity
Range of genes available within a species
What is speciation
When new types of species are developed through isolation
What are the steps of natural selection
Genetic variation causes some individuals to be better suited to an environment, overtime these favourable traits become more common in the population.
What is selective advantage
A characteristic that enable an organism to survive and reproduce better than the other organisms in that population
What is selection pressure
External agent that affects an organisms chance of survival depending on genotype. The effects of this can change the occurance of a trait overtime
What is geographic isolation
Isolation caused by a geographical barrier dividing the population into 2
What is reproductive isolation
With enough time the genetic information will change eventually enough difference will accumulate that the two populations can’t breed and is now two different species
What is artificial selection or selective breeding
Breeding for favorable traits for humans.
Why do we use selective breeding
To increase crop yield of plants, animals for food, fibre or meat.
What is the downfall of selective breeding and GMO’s
It decreases biodiversity of the species
What is gene therapy
When faulty genes are removed from chromosomes
What are GMO’s
Genetically modified organisms. When the specific genes of an organism are altered for desired traits eg frost resistant
What is the evidence for evolution
Fossils, molecule biology, and comparitive systems
What are fossils
Ancient remains of animals or plants that provied physical evidence about which organism lived on earth in the past.
What does the fossil record indicate
An increase in complexity and diversity overtime, it allows evolutionary links to be made
What is comparitive embroyology
Closely related organisms show similar anatomical development in the embryo. Many features are not present in adulthood, provided evidence for common ancerstry
What are vestigal structures
The structures are remains of organs that were required in ancestral form but don’t serve any purpose now. Natural selection pressures has done this as we don’t need them and to not waste energy
Homologous structures
Structures with similar architecture but they perform different things in different organism this shows they have a common ancestor
