The idea that life changes over time didn't begin with
Charles Darwin. Long before him, ancient Greek philosophers and early Christian
scholars engaged in discussions about how life may have developed or evolved.
However, these discussions faded during the Middle Ages, when religious
doctrine took precedence. During this period, the belief that all life forms
were fixed and created exactly as they appear today—based on literal
interpretations of Biblical scripture—became dominant.
Fossil Discoveries Spark New Questions
By the 1700s, this belief in fixed life forms was
increasingly challenged. As more and more fossils were unearthed, naturalists
began to question whether organisms had really remained unchanged since the
moment of creation. These discoveries laid the foundation for a renewed
interest in the possibility of biological evolution.
Early Evolutionary Theories and
Influencers
Inheritance of Acquired Traits: An
Ancient Idea
One of the earliest evolutionary concepts—inheritance of
acquired characteristics—has its origins in ancient Greek philosophy. The idea
was that organisms could pass on traits they developed during their lifetime to
their offspring. This concept later gained traction in scientific circles
through the work of Erasmus Darwin, the grandfather of Charles Darwin. In his
book Zoonomia (1794–1796), Erasmus suggested that life evolved gradually
over millions of years, a radical idea at a time when many still accepted
Bishop Ussher’s 1654 claim that the Earth was created in 4004 BCE.
Lamarck’s Theory of Evolution
Jean-Baptiste Lamarck: The First
Evolutionary Scientist
Jean-Baptiste Lamarck, a French army veteran turned
botanist, became one of the first scientists to propose a comprehensive theory
of evolution. Known for coining the term “invertebrates,” Lamarck published Philosophie
Zoologique in 1809, where he outlined his theory that life evolves not
through sudden catastrophes but through gradual adaptation to the environment.
Lamarck’s Key Ideas
Lamarck believed that organisms adapt to their surroundings
through use and disuse of body parts. If an organism frequently used a
particular organ or structure, it would grow stronger or larger during its
lifetime—and these changes would be passed down to its offspring. He famously
used the giraffe as an example, suggesting that generations of giraffes
stretched their necks to reach higher leaves, leading to the evolution of long
necks. Similarly, he proposed that birds developed long legs by stretching them
to wade through water, while unused parts, like limbs in snakes, would shrink
over time and eventually disappear.
Rejection and Rediscovery
Criticism and Legacy
Despite Lamarck’s detailed reasoning, his theory was
rejected by many during his lifetime. Both religious authorities and many in
the scientific community dismissed his ideas, viewing them as unproven and
incompatible with prevailing beliefs. Lamarck died in poverty, blind and largely
unacknowledged for his contributions.
A Modern Reassessment: Epigenetics and
Lamarckism
Today, some of Lamarck’s ideas are being re-evaluated in the
light of modern epigenetics. While his original mechanisms have not been
supported by genetic science, new research suggests that environmental factors
can indeed influence gene expression and be passed on to future
generations—echoing some aspects of Lamarck’s theory, albeit through entirely
different biological processes.
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| Lamarck cited the giraffe as a key example of how acquired physical characteristics can be passed down through generations. He theorized that the giraffe's long neck evolved from its ancestors stretching their necks over time to reach the highest leaves in trees. |
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