Hi! I dont really like see much of an difference between Darwin and Lamarck. Can you help me?
Sure I can help you.
Lamarck (1744-1829) believed that traits that one ACQUIRED could be passed on to the next generation. The usual prime example for his idea is that if a giraffe stretched his neck often enough, it would be longer. And that longer neck would then be inherited by its offspring. It is in this way, he reasoned, that giraffe have such long necks. Clearly this isn't true. One can have litter after litter of puppies, and dock every single tail....an acquired trait. Never, will there be a puppy born to any of those canine parents with a gene for a docked tail. Lamarck lived before Darwin, but even before his life ended, the idea of inherited acquired traits made no sense.
Darwin,(1809-1882) on the other hand hardly knew what he was looking at when he reached the Galapagos Islands in 1835. It wasn't until he returned to England, and put all his notes together that he realize how wrong Lamarck was. The difference between the two is that Darwin did in the end.... beginning likely in the late 1840's......understand that all animals and plants all the time are filled with mutations...goofs in transmitting the genetic code to the offspring. And of those mutation, most are harmless..... just DNA junk. (Though he did not know about DNA nor genes, nor was he aware of the research with pea plants by Mendel.)
But every so often, there is one gene that is slightly better, say, allowing an animal to run just a bit faster, or see a bit better, or fly a bit higher. And even if it is only a 2 or 3% improvement, in 40 or so generations, all the animals of that species in that area will have that gene, and no other for that specific part of its anatomy.
On the other hand, if the mutation is lethal.... (an offspring born with a heart outside the body, a head with no brain, Most of the spinal chord gone, etc.....) that offspring will die, and with it, at least until it pops up again generations later, the gene for that defect will not be inherited, since the carrier never makes it to adulthood to breed and pass it on.
The key to understanding Darwin is to realize that MUTATIONS occur all the time, and NATURE SELECTS the animals/plants with the best mutations. It is pressures in the environment that drive mutations to be successful ones. And those same pressures end the existence of individuals with lethal genes.
Darwin in his later years even did some predicting. I'm sure he never made it to Madagascar, but someone wrote to him that there was a night blooming orchid that had a pollen tube a foot long. What on earth could pollinate such a plant???? Darwin knew that birds do not pollinate at night, he suggested that it likely was a moth with a foot long tongue. No one found anything for decades, and in the 50 years from 1850 to 1900, huge, and vast swaths of that island's habitats were destroyed from logging, clear cutting for farming, and mining. You'd think for sure that if a moth were the pollinator, it would long ago have become extinct.
Nope !!!!!!! In 1903,long after his death, the moth was found. It is now called a Morgan's Hawk Moth, and it indeed has a tongue a foot long. Go to Bugguide.net, and plug in the name. There likely is a photograph of one....along with its foot long tongue.
Sadly, for his marriage, he and his wife, never agreed that evolution was true. He'd walk her and the children to church, but he simply strolled past the church and went for a walk...when he could. He had contracted Chaga's Disease while in South America in the 1830's. (google it) Even today, there is no cure.
Because it causes painful arthritis, the later photos of Darwin show him with a full beard.... it was too painful to shave.
Contrary to the opinions of some evangelical Christians, Darwin made no death bed confession that he was wrong. He remained a staunch atheist the rest of his life.
To this day, the idea of evolution is one of the greatest ideas ever having been penned. There were several scientists on the same track, but all deferred to Darwin as the one who ought to have the credit for this idea.
Interestingly, however, even ancient Greeks noticed common traits in all animals with an internal skeleton....all had a head, body, four limbs and a tail....(yes, all humans have a tail---most are not external. In poor, Third World countries, many are not removed, since families can then display the child for money. Some individuals have the ability to wiggle the tail.)
If I've added for you more question, please feel free to write again.