Natural selection Flashcards
(24 cards)
What is evolution?
The change in a species or a change in population in a specific environment.
How can populations evolve?
Sometimes populations evolve rapidly (bacterial resistance) or take place over long periods (giraffe evolution).
Who proposed an explanation for the diversities among species?
Jean Lamarck.
What did Lamarck suggest about organisms?
Organisms adapt to their environment through changes in their characteristics.
What is the concept of ‘Use and Disuse’?
Organisms lost parts because they were not used (like the missing eyes and digestive system of the tapeworm).
What happens with ‘Perfection with use and need’?
The constant use of an organ leads that organ to develop (like the muscles of a blacksmith or the large ears of a night-flying bat).
What did Lamarck believe about acquired characteristics?
He believed they could be transmitted to the next generation.
Who is Charles Darwin?
A British naturalist.
Where did Darwin travel?
He traveled around the world and stopped at the Galapagos Islands.
What did Darwin discover about species on the Galapagos?
Most of the species live nowhere else in the world but resemble species living on the South America mainland.
What correlation did Darwin find with Finches?
He discovered several species of Finches that correlated to food sources.
What leads to adaptations?
Natural selection leads to adaptations.
What is an adaptation?
Any trait that makes an organism better suited to its environment.
What are the benefits of adaptations?
Avoid being eaten, better attract a mate, better bearing/raising offspring, better utilize a specific resource, etc.
What happens to the most successful individuals in natural selection?
They are best adapted due to their fitness.
What is fitness in the context of natural selection?
The ability to pass traits to the next generation.
How did Lamarck explain giraffe necks?
He believed giraffes reached high vegetation, stretched their necks, and transmitted the longer neck to offspring.
How did Darwin explain giraffe necks?
He believed giraffes with longer necks survived better and had offspring that inherited their long necks.
What is reproductive success?
Individuals with the most advantageous phenotype leave more viable offspring.
What is natural selection often referred to as?
Survival of the fittest, because the most fit organisms survive and reproduce.
What is an example of natural selection?
Antibiotic resistance in bacteria: Antibiotics don’t kill all individuals; resistant individuals survive and reproduce resistance.
What happened to Peppered Moths during the Industrial Revolution?
Light-colored moths were more common until soot covered the trees, allowing dark-colored moths to blend in.
What is selective breeding?
Occurs when humans affect variation in other species by choosing which traits are desirable.
Give an example of selective breeding.
Breeding dogs, horses, livestock, and crops.
