BIOL 102 1st Edition Lecture 1 Outline of Last Lecture:I. Overview of the syllabusOutline of Current Lecture:I. Theory of adaptation and evolutionII. Charles Darwin III. Natural SelectionCurrent Lecture: Theory of Adaptation and Evolution- Theory- in the scientific community it’s as close to fact we can get based on the information we have.- An explanation for some of the questions we have and why things are different.- Evolution- changes over time to populations or groups to become better adapted to the environment.- Adaptation- something that changes or acquires a new trait that makes you more fit for your environment. - Different kinds of adaptation:o Behavioral (ex. ability to learn)o Structural (ex. giraffes with long necks in order to reach leaves)o Biochemical (ex. metabolism speed)o Physiological (ex. venom in a snake, prevents others from attacking it by developing a defense system)Charles Darwin- Early Life- Collected bugs as a child- Father was a physician and made him go to medical school- People who knew him described Darwin as a “wimp”- Darwin dropped out of medical school and went to school to become a minister and graduated with a bachelor’s degree.- His professor was going to travel and needed someone to collect specimens on his voyage so he invited along Darwin.- Galapagos Islands- Off the coast of South Africa- This trip shaped Darwin’s theory of evolution- Discovered a fossil of a land sloth (picture p.293) under layers of seashellso Darwin hypothesized that perhaps the environment had changed. That MAYBE it wasn’t always a place with a lot of water and the land sloth died because it could not survive in this new environment.- Darwin’s time was influenced a lot by Aristotle and Christian beliefso A lot of speculation in the scientific community Maybe the Earth is older than we thought Maybe species and environments have changed over time over a gradual time period- Darwin did not want to initially publish or discuss any of his findings because he knew it would cause controversy and chaos in the scientific community - Lamarckian evolution (came out the year Darwin was born, expanded on Aristotle’s previous model) Humans highest on the evolutionary ladder Vertebrates Invertebrates Land plants Green algae Fungi bacteria lowest on the laddero Lamarck believed that you could acquire new traits during your lifetime and move up the ladder- Lamarck’s beliefs:o Change over timeo Acquired characteristics Ex. A giraffe has a short neck; it’ll stretch and strain its next to reach the leaves in the tree until it becomes long enough over time and can reach the leaves. When the giraffe has children, the offspring will have long stretched necks. That’s like if someone got into an accident and lost a limb, saying that when they have children, their children will be born missing alimb.Natural Selection- Natural Selection- the mechanism that causes change over time- The natural environment determines what traits are or are not
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