According to extensive scientific evidence and fossil records scientists have noticed a dramatic decrease in the size and volume of the human brain over the course of 200,000 years. decreased cranial volume has in turn resulted in decreases in brain mass, irrespective of gender and race. scientists are still puzzled as to what may have caused this trend but there are three prevailing theories as to the shrinking mechanism.
It is thought that climate change has played a significant role in the decrease in human brain size. because larger bodies are better at conserving heat, a larger physique would have been tremendously beneficial in the colder climates of the past. as global temperatures rose, natural selection might have favored humans with slighter and smaller frames. following this logic, as bodies, skeletons, and skulls shrank, the brain also followed suit.
A second popular theory correlates the decreased brain size to widespread transitions to agricultural civilizations. geographically disparate civilizations adopted technologies and practices that made agriculture more viable than hunting and gathering. paradoxically, the agricultural revolution resulted in diminished nutrition consumption because grain diets lacked sufficient vitamins and proteins vital to the growth of the body and brain. in response to chronic malnutrition, our brain might have shrunk to conserve energy.
A third theory postulates that as human muscle mass decreased, so did our brains. comparison of remains of millennia-old skeletons, distant ancestors of the modern human, indicate a considerable loss of muscle mass as time went on. this decrease in mass may be attributed to an overall decrease in aggression in humans. simply put the stronger and larger we are the more gray matter we need to control massive muscle blocks. as humans dropped muscle mass, there was less need of large brains to control the remaining muscles. in the end, we have a brain that has decreased both in absolute terms and relative to our stature.
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学术讨论
We’ve been discussing the importance of hiring and retaining highly skilled
employees, but even the best employees may need to periodically update or further develop their work skills. One question facing managers is how much time and money to invest in improving the work skills of their employees. Some managers argue that ongoing employee training is the most important investment a company can make.
What are your thoughts on the matter?
Andrew的观点：
I don’t think that employee training is the most important investment a company can make. The company should be hiring the most skilled workers it can find in the first place. There are so many other unavoidable things that a company needs to spend money on that have to take precedence over training.
Kelly的观点：
Employees’ leaving their jobs is always a risk, but providing ongoing training and skill development is more likely to make employees want to stay rather than go, in my opinion. When employers pay for training, employees are likely to feel more valued by their employer, and this can only improve the employer-employee relationship.
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