22 Questions
What is the main idea behind Lamarckism?
Traits acquired during an organism's lifetime can be passed on to its offspring
How did Lamarck explain the development of longer necks in giraffes?
By stretching their necks to reach higher leaves, giraffes acquired longer necks which were passed on to offspring
Which theory proposed that evolution occurs through the survival of the fittest?
Darwin's Theory of Natural Selection
What major criticism is often directed at Lamarckism?
It contradicts the principle that acquired traits cannot be inherited
What is the main concept behind Darwin's theory of natural selection?
Survival and reproduction of organisms with advantageous traits
How does Lamarckism differ from Darwin's theory of natural selection?
Lamarckism proposes the inheritance of acquired characteristics, whereas Darwin's theory does not.
Why did Lamarck's theory fail to provide a robust explanation for how species evolve?
It lacked empirical evidence to support its claims.
Which concept has been largely discredited in evolutionary biology due to empirical evidence?
Inheritance of acquired characteristics
What is the primary reason why evolutionary biologists rely on Darwin's theory of natural selection today?
It provides a robust and testable explanation for adaptations and changes in living organisms.
In the context of evolution, what does 'adaptation' primarily refer to?
Traits that increase an organism's ability to survive and reproduce in its environment.
What is the primary mechanism of evolution described in the text?
Natural Selection
Which phenomenon led to the increase in the population of black moths in urban areas during the nineteenth century?
Industrialization and Sooty Air Pollution
What key concept in evolutionary biology is exemplified by the story of the black and pale moths?
Natural Selection
In the context of the moth example, which scientific theory would best explain the shift in moth coloration over generations?
Modern Synthesis Theory
According to Lamarckism, how are physical changes acquired by an individual during its lifetime passed on to its offspring?
Through inheritance of acquired characters
Which of the following is a key feature of Lamarck's theory regarding the development of organisms?
Organisms are driven to greater complexity through adaptation
How does Lamarckism differ from Darwin's theory of natural selection regarding the mechanism of evolution?
Lamarckism suggests adaptations occur through random genetic mutations
In Lamarck's theory, what role does the environment play in driving changes in organisms?
The environment influences new needs in organisms
What term did the scientist use to describe the phenotypically different offspring of the evening primrose plants?
Mutants
What did the scientist observe about the number of chromosomes in plants as their varieties changed?
The number of chromosomes increased
What did the scientist refer to as 'saltations' in the context of evolution?
Sudden and large inheritable changes in genetic makeup
Which concept does Neo-Darwinism involve as one of its postulates?
Gene variability and natural selection
Study Notes
Lamarckism and Darwin's Natural Selection: Evolution's Tale of Two Theories
Jean-Baptiste Lamarck and Charles Darwin may be two of the most influential figures in the history of biology, each leaving their indelible mark on our understanding of how life evolves. Their theories, while alike in the broad scope of explaining change over time, differed in key ways. Let's dive into the beginnings of evolutionary biology, exploring Lamarckism and Darwin's theory of natural selection.
Lamarckism: Inheritance of Acquired Characteristics
Lamarck (1744-1829) proposed that living organisms progressively develop new traits throughout their lifetime, and these new traits could be passed on to their offspring. His theory, known as Lamarckism or the inheritance of acquired characteristics, suggested that if a lion strained its neck to eat leaves from trees, its neck would become longer. This longer neck would then be passed down to its descendants.
Jean-Baptiste Lamarck
While Lamarck made significant contributions to the classification of organisms, Lamarckism ultimately failed to explain the vast majority of evolutionary changes observed in nature.
Darwin's Theory of Natural Selection
Almost a century after Lamarck, Darwin (1809-1882) proposed his theory of natural selection. Darwin's theory explained how species evolve through time by favoring certain traits that increase an organism's ability to survive and reproduce in its environment. He argued that over generations, those possessing advantageous traits would be more likely to survive and pass their genes on to their offspring.
The Origin of Species
Darwin's theory, outlined in his seminal work, "On the Origin of Species," was much more successful at describing the processes of evolution. His ideas were supported by empirical evidence, particularly the well-documented observations of variation in species and the fossil record showing the appearance and extinction of many species.
Adaptation: The Common Thread
Both Lamarckism and Darwin's theory of natural selection share a common theme: they explain how species change over time. However, Lamarck's theory failed to provide a solid basis for how species evolve, while Darwin's theory provided a robust and testable explanation for the changes observed in nature.
Today, evolutionary biologists primarily rely on Darwin's theory of natural selection to explain the adaptations and changes in living organisms. The inheritance of acquired characteristics is now understood to be a misconception that has been largely discredited.
Understanding the evolutionary history of our planet is a fascinating endeavor, peppered with the successes and failures of the various theories that have tried to explain the origins of life, adaptation, and the complexity of nature. Lamarck's and Darwin's theories, while different, both contributed to the rich landscape of our understanding of evolution, adapting and evolving to better explain the world we live in.
Test your knowledge on the theories of Lamarckism and Darwin's natural selection in the history of evolutionary biology. Explore the contrasting ideas of how species evolve over time and the impact of inherited traits on future generations.
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