Evolution Flashcards
What is evolution?
A change in the genetic traits in a population over many generations. Evolution occurs over generations through repeated genetic variation, natural selection and reproduction.
What is an acquired trait?
A feature that is gained during an individual’s lifetime
Acquired traits, such as scars and learned skills, cannot result in the evolution of a population.
What is an adaptation?
A genetic trait that helps an organism survive in its environment
What is an antibiotic?
A medicine that kills bacteria or prevents their growth
What is an antibiotic-resistant?
Able to survive in the presence of antibiotics. Some bacteria have evolved antibiotic resistance and are known as superbugs.
What is a behavioural adaptation?
A behaviour or action that helps an organism survive. Behavioural adaptations include migrating, burrowing and building dams or nests.
What is a common ancestor?
A species that two or more other species have evolved from. The common ancestor of humans and sharks lived about 470 million years ago.
What is competition?
The struggle between organisms for resources, such as food or mates. Competition means that many organisms will not survive long enough to reproduce.
What is an evolutionary tree?
A diagram that shows how species are related. An evolutionary tree shows how related species evolved from common ancestors.
What is an extinction?
The dying out or complete disappearance of a species. A species is said to be extinct when the last individual of that species has died.
What is genetic diversity?
The amount of genetic variation in a population. Genetic variation is needed for evolution because it makes some individuals better adapted to the environment than others.
What is a genetic trait
A feature that can be passed down by genes to the next generation.
Genetic traits, such as neck length and fur colour, can result in the evolution of a population.
What is mutation?
A small random change in an organism’s DNA
Mutations can be passed on to offspring through reproduction, increasing the genetic variation in a population.
What is natural selection?
The survival of organisms that are better adapted to their environment
What is physiological adaptation?
An internal bodily process that helps an organism survive
Physiological adaptations include production of venom and regulation of body temperature.
What is a population?
A group of organisms of the same species living in the same place
What is a selection pressure?
A challenge that affects an organism’s ability to survive and reproduce
Selection pressures include hunting by predators, access to resources, diseases and weather conditions.
What is speciation?
The formation of a new species
Speciation occurs when a population splits into two isolated populations that evolve under different selection pressures
What is species?
A group of similar organisms that can breed to produce fertile offspring
What is structural adaptation?
A physical feature of the body that helps an organism survive
Structural adaptations include scales, fur, feathers, long tails and bright colours.
What is variation?
A difference in traits between individuals of the same species
Variations in genetic traits arise because of mutations. Some traits provide an advantage for survival or reproduction.
