UPCAT Biology — EvolutionFlash Cards

Who is considered the father of the theory of evolution?

Charles Darwin is considered the father of the theory of evolution. He developed the theory of biological evolution through extensive research during his voyage on the HMS Beagle and published his findings in 'On the Origin of Species' in 1859.

What is Darwin's theory of evolution?

Darwin's theory states that all species of organisms arise and develop through the natural selection of variations in traits that enhance an organism's ability to survive, compete, and reproduce. This process leads to changes in species over time.

What is natural selection?

Natural selection is the process by which organisms with favorable traits that help them survive and reproduce in their environment are more likely to pass these traits to their offspring. Over time, this leads to changes in the population and eventually to evolution.

What are the key requirements for natural selection to occur?

Natural selection requires: 1) Variation - individuals in a population must have different traits, 2) Inheritance - traits must be heritable and passed to offspring, 3) Selection pressure - environmental factors that affect survival and reproduction, 4) Time - sufficient generations for changes to accumulate.

Who proposed the theory that preceded Darwin's, focusing on use and disuse?

Jean-Baptiste Lamarck proposed an earlier theory of evolution. His theory included the Law of Use and Disuse, which suggested that organs become stronger through use and weaker through disuse, and that these acquired traits could be inherited.

What is Lamarck's Law of Use and Disuse?

Lamarck's Law of Use and Disuse states that the more an animal uses a certain part of the body, the better and stronger it becomes. Conversely, organs that are not used become weaker. He believed these changes could be passed to offspring through inheritance of acquired characteristics.

According to Lamarck, can traits developed through environmental challenges be inherited?

Yes, according to Lamarck's theory, traits developed through environmental challenges, such as organ developments, can be inherited by offspring. This concept is called the inheritance of acquired characteristics, though we now know this is generally incorrect.

Compare Darwin's and Lamarck's theories of evolution.

Darwin's theory: Evolution occurs through natural selection of inherited traits that improve survival. Lamarck's theory: Evolution occurs through use and disuse of organs, with acquired traits being inherited. Darwin's theory is scientifically accepted today, while Lamarck's inheritance of acquired characteristics has been largely disproven.

What is biological evolution?

Biological evolution is the change in heritable traits of biological populations over successive generations. It results in the diversity of life forms we see today, from simple single-celled organisms to complex multicellular organisms including humans.

What role does variation play in evolution?

Variation provides the raw material for evolution. Without genetic differences between individuals in a population, natural selection would have nothing to act upon. Variations arise through mutations, genetic recombination, and other genetic processes.

What is adaptation in evolutionary terms?

Adaptation is a trait that enhances an organism's ability to survive and reproduce in its specific environment. Adaptations develop over many generations through natural selection and make organisms better suited to their ecological niche.

Give an example of how natural selection might work in a population of beetles.

In a population of beetles where some are green and others brown, if they live in a forest with brown bark, the brown beetles would be better camouflaged from predators. More brown beetles would survive and reproduce, passing the brown color trait to their offspring. Over time, the population would have more brown beetles.

What is the difference between acquired traits and inherited traits?

Inherited traits are genetically determined characteristics passed from parents to offspring through genes (like eye color). Acquired traits are characteristics developed during an organism's lifetime through environmental influence (like muscle strength from exercise). Only inherited traits contribute to evolution.

Why is Lamarck's theory of inheritance of acquired characteristics considered incorrect?

Lamarck's theory is incorrect because acquired characteristics during an organism's lifetime (like muscle development from exercise) are not encoded in the DNA and cannot be passed to offspring. Only genetic traits present in reproductive cells can be inherited.

What evidence supports Darwin's theory of evolution?

Evidence includes: fossil records showing species changes over time, comparative anatomy revealing similar bone structures in different species, biogeography showing species distribution patterns, molecular biology revealing DNA similarities, and direct observation of evolution in laboratory and natural settings.

What is survival of the fittest?

Survival of the fittest means that organisms best adapted to their environment are more likely to survive and reproduce successfully. 'Fitness' in evolutionary terms refers to reproductive success, not physical strength. The 'fittest' organisms pass more of their genes to the next generation.

How do environmental pressures drive evolution?

Environmental pressures (like climate change, predators, disease, competition) create selection forces that favor certain traits over others. Organisms with advantageous traits survive and reproduce more successfully, leading to these traits becoming more common in the population over generations.

What is the relationship between competition and evolution?

Competition for limited resources (food, mates, territory) drives natural selection by favoring individuals with traits that give them advantages in obtaining these resources. Successful competitors are more likely to survive and reproduce, passing competitive traits to their offspring.

Why does evolution require many generations to show significant changes?

Evolution requires many generations because: 1) Small genetic changes accumulate slowly, 2) Natural selection acts on populations, not individuals, 3) Environmental pressures may fluctuate, 4) Beneficial mutations are rare, and 5) Complex traits involve multiple genes that change gradually over time.

What is the modern understanding of evolution called, and how does it differ from Darwin's original theory?

The modern understanding is called the Modern Evolutionary Synthesis or Neo-Darwinism. It combines Darwin's natural selection with modern genetics, understanding DNA, mutations, and inheritance patterns. Unlike Darwin's theory, it explains the molecular mechanisms behind heredity and variation.