It is the GCSE Biology exam for my AQA students tomorrow. And one of the key topics in the B2 part of the syllabus is on Genetics and the work of Gregor Mendel. Mendel was an Austrian monk and Biologist in the 19th century. Mendel was very systematic and methodical in his experiments with peas. He was able to work out that traits can be inherited by future generations. And that there are dominant and recessive characteristics. We know these as alleles now.
This short 3 minute video is a great introduction into Punnett squares and the basics of genetic inheritance. Mendel was a pioneer of his time as we didn’t know about DNA or Chromosomes in the 19th century. The animations of the peas in this video are also very engaging and funny.
Did you know that the world population took all of evolutionary time to reach the 1 billion mark at around the year 1800 and then between 1999 and 2011, we added another billion in just the space of 12 years? 12 years Vs all the time since the beginning of time, my head just hurts trying to even think about this! The world’s population has done some staggering things over the last 200 years, and it is hard to comprehend this with just looking at the raw numbers. A new video by the AMNH however clarifies this very well.
This latest video by The American Museum of Natural History (AMNH) is directly relevant at GCSE Biology (AQA B3 module “Humans and their environment”) and Geography. Besides that it is a superb demonstration in maths about linear Vs exponential growth. But even more than that the implications of populations growth are directly relevant to each and every one of us.
I can think of three very critical times that represent a major shift in the way humanity has changed.
Spreading out of Africa 100,000 years ago and spreading across the rest of the world as hunter gatherers. Modern humans are believed to have evolved in Africa 200,000 years ago. After that it is believed that a very small number of hunter gatherers were able to start migrating out of the African continent. While there are different theories about the exact nature of this migration, there is very little scientific doubt left that all of humanity originates from Africa.
Discovery of farming 10,000 BC approx. The discovery of agriculture is more recent in the big scheme of things. It is hard to imagine a world without agriculture now, or that we weren’t actually evolved to live in an agricultural society. Yet many of our social ideas have come about from agrarian societies, including the idea of currency and money. In his book Cialdini explains that reciprocity and exchange are evolutionary built in us. That idea of reciprocity when extended out in the context of land ownership in an agricultural society with grains as everlasting currency gave birth to the more tangible idea of wealth and money. Eventually being abstracted in the form of coins and bank notes.
The Industrial Revolution mid 1700s. This totally changed everything again, and to date the population explosion can be explained by modern medicine, urbanisation and the industrial age. The start of the 1900s saw the start of the current population explosion. The discovery of antibiotics in 1928 well and truly added to this population growth. We beat the bugs, and there has been no stopping in our population growth since. But with antibiotic resistance on the rise we risk being taken back in time.
These numbers and facts are what current evidence by Science tell us. The good news is that fertility rates across the world are now decreasing and even now, the rate of population increase is going down. This means that the population won’t keep increasing forever and it will level off in 2100. An average estimate brings this figure to 11 billion in the year 2100. But there’s slight variation in this possible as projections cannot be 100% accurate.
The beautifully captioned video shows a simple graph of the population of the world increasing with time, and all the major historical events to go along the timeline to give us a point of reference. The music is what makes it though and is truly captivating. So enjoy the ride this video takes you on.
What are your thoughts on the population growth and what questions does this get you thinking of? Let me know below through comments.