Science & Nature Archive

Monday, April 30, 2018

Annoyed at Headlines - Star Trek Wasn't Prophetic on Brain Death

Starfleet LogoI know that science reporting ain't what it used to be. And even in the 'old days', when newspapers had decent sized science departments, headlines could be misleading. Still, the reporting on a recent study has irked me enough to become a cranky old man and call it out here on my blog.

Here are a few examples of the coverage. Pay attention to what those headlines are implying.

Here's how Vice summarized the findings of the study.

[Jans] Dreier works at the Charité Hospital in Berlin, one of Germany's leading university hospitals. In February, the 52-year-old and his colleague, Jed Hartings, published a study that details what happens to our brain at the point of death. It describes how the brain's neurons transmit electrical signals with full force one last time before they completely die off. Though this phenomenon, popularly known in the medical community as a "brain tsunami," had previously only been seen in animals, Dreier and Hartings were able to show it in humans as they died. Their work goes on to suggest that in certain circumstances, the process could be stopped entirely, theorizing that it could be done if enough oxygen is supplied to the brain before the cells are destroyed.

About 2/3 of the way through that Vice article, you find the following interview question and answer with the study author.

So how did you find out that an episode of Star Trek had predicted your findings 30 years ago?

My colleague, Jed Hartings, brought it to my attention after watching the scene and noticing how similar it is to our work. My best guess is that the creators of Star Trek must have found research at the time that detailed a similar process in animals. The first person to research these sort of brain waves was a Brazilian neurophysiologist who conducted studies on rabbits in the 1940s. All we've done is show it in humans, which has taken this long because medical research in general is an incredibly slow process.

So in reality, this is a process first studied in the 1940s. The big innovation in this study is that it was done on human subjects, rather that non-human animals, but it shouldn't be a shock at all that human brains function the same as other mammal brains. So, Star Trek's writers back in the '80s were just using an already known phenomenon in their script. You could praise the writers for getting the science right (because they didn't always), but it's not like they made some profound prediction that science is only now catching up with.

All this isn't to say that the new study isn't fascinating. Of course it's interesting to do this study on actual people instead of other animals. But it doesn't sound like it found anything that wasn't already expected.

Image Source: Wikimedia Commons

Monday, February 12, 2018

One More Darwin Day Link

Ape Skeletons

I just came across this article by Scott Solomon, so I thought I'd pass it on:

If you recall, Scott wrote the recent book, Future Humans, so he's in a good position to discuss recent human evolution. Go see what he had to say for Darwin Day.

Image Source: Houston Chronicle

Happy Darwin Day 2018

Darwin's BirthdayToday is Darwin Day, the 209th anniversary of Charles Darwin's birth. To reuse the same thing I've written for a few years now (origianlly here), Charles Darwin was "the man who presented evolution in such a way and with sufficient evidence that it became obvious that it was the explanation for how life developed on this planet. Others had ideas of transmutation before Darwin, and Alfred Russel Wallace even came up with a theory of natural selection very similar to Darwin's at around the same time, so it's apparent that humanity would have eventually recognized how evolution works. But Darwin's genius in presenting all the evidence for evolution in the way he did certainly gave the field a huge head start."

Although Darwin Day this year isn't getting anywhere the same attention as the bicentennial of Darwin's birth a few years ago, there are still Darwin Day events at various locations. If you want to see if there's anything near you, you can check out the list of events at DarwinDay.org. (I checked there and local calendars, but couldn't find anything for today in Wichita Falls.)

To celebrate Darwin Day on this site, I just posted a new entry today giving a concrete example of speciation:

Since the last Darwin Day, I've also created a section on this site highlighting some of my better writings on evolution, as a starting point for people who may not understand it very well. There are actually several entries there that are new since Darwin Day last year, so go check it out.

And here are a couple more entries I've written about Darwin that are appropriate for today.

Finally, here are links to external sites with good information about Darwin and evolution. The first is brand new this year, the next two are from the bicentennial celebration a few years ago, and the last is just a classic that's been around for years.

  • Oxford University Press - Darwin Day 2018 A great collection of links to articles and resources about Darwin.
  • Nature's Darwin 200 The prestigious journal has put together a collection of articles, editorials, news stories, and various other essays and features that have to do with evolution in general or Darwin in particular.
  • American Museum of Natural History's Darwin page Yet another good collection of information. This is from the exhibit that ran in the museum from 2005 to 2006.
  • The TalkOrigins Archive Has a bit more focus on the creation/evolution controversy rather than just straight science, and hasn't really had too many recent updates, but it is still very, very informative.

Evolution in Action - The Ongoing Speciation Event of Apple Maggot Flies

This entry is part of a collection on Understanding Evolution. For other entries in this collection, follow that link.


Apple Maggot FlyA little while ago, I came across a question on Quora, When gorillas and humans split from their common ancestor was there a 'new' individual of each new species born at that time?. Since other people had already discussed human evolution specifically, I decided to go with a more concrete example of an ongoing speciation event happening before our very eyes. Here's that answer, slightly edited.

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I'm going to give a concrete example - apple maggot flies. A few hundred years ago, there were no apple maggot flies, because there were no apples in the Americas. Apples weren't brought to the Americas until the 17th century. Now, there were obviously other types of trees and fruits in the Americas before that, and different types of insects that fed on them. One type of fruit bearing tree was the hawthorne, which was fed upon by hawthorne flies. You can probably see where this is heading.

Once Europeans brought apple trees to the Americas, there was a whole new potential food source for these flies. Some time in the early 1800s, some hawthorne flies began eating apples. They were still the same species as their relatives that ate hawthornes, without any drastic differences. They just had a few mutations that made them preferentially seek out apples as opposed to hawthornes. If anyone had put them in close contact with flies that still ate hawthornes, they wouldn't have had any trouble breeding.

Well, as the years went by, the flies that preferred apples began to get more and more distant from their hawthorne eating relatives. For one, since they were physically on apple trees more often than hawthornes, they mated more often with other apple eating flies. And since apples ripen earlier than hawthornes, the apple eating flies timed their emergence from their pupae to occur earlier in the year, introducing a separation in time, as well (obviously, this timing was based on genetic mutations, not conscious choice by the flies). Since each group of flies was more likely to mate with flies that ate the same type of fruit, any mutations that were appearing in the two different groups were more likely to remain in that particular group, and not be shared with the other group. So, the populations of apple maggot flies and hawthorne flies have been growing more genetically distinct.

Today, they are still classified as the same species, because flies from one group can still mate with flies from the other group to produce fertile offspring. But those hybrid offspring are less likely to survive because they'll have a mix of genetics from their parents, making them less specialized for eating either hawthornes or apples. The hybrids aren't completely doomed to dying without mating themselves, but because their chances are lower than non-hybrids, it further reduces the the gene flow between the two populations. If things continue as they are, these two populations will probably end up becoming two distinct species.

That's how speciation occurs. It's not something that occurs over a single generation. It's a process that takes many generations to complete. And the two incipient species are initially very similar. It's only many, many generations later, once each lineage has had a chance to evolve independently, that the two species start to show bigger differences.

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To answer the original Quora question regarding human evolution, millions of years ago when a certain population of apes gave rise to two different lineages - one that would eventually give rise to gorillas, and the other that would eventually give rise to chimps, bonobos, and us, it would have occurred in much the same way. At first there were two populations that were still the same species but just separated somehow. Once separated, they acquired unique mutations in each lineage. Eventually, many generations later, they were two distinct populations that could no longer interbreed - two separate, but closely related and very similar species. Only that speciation event would have taken longer than the current ongoing hawthorne/apple maggot fly event, because generations in apes are much longer than those of fruit flies.

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More Info:

Image Source: Wikipedia


Want to learn more about evolution? Find more at Understanding Evolution

Tuesday, December 5, 2017

An Early Christmas Present - Koch Snowflake Christmas Ornament 3D Printer STL Files

Koch Fractal SnowflakesI've had a 3D printer for a little while, now. While I mostly experiment with printing out various concept aircraft, I figured that for Christmas, I'd print a few Christmas ornaments. But with me being the nerd I am, I couldn't just print out any old random ornament. It had to be something a bit nerdier. So, after reading a post on Scientific American Blogs, A Few of My Favorite Spaces: The Koch Snowflake - A look at the most festive fractal, I was inspired to print a few tangible interpretations of the fractal. And I've shared the STL files below, for anybody else who might want to make them.

But first, here's a really cool animated gif from that Scientific American article, originally from Wikimedia Commons, showing the development of this fractal.

Koch Snowflake Fractal
Image Source: Wikimedia Commons, Credit: António Miguel de Campos

And here are the STL files. I've put a preview of each model. Clicking on the thumbnail will show a higher resolution image. To download the STL, use the actual download link.

Koch Snowflake 1 Preview Download Koch_Snowflake_1.STL
  
Koch Snowflake 1 Preview Download Koch_Snowflake_2.STL
  
Koch Snowflake 1 Preview Download Koch_Snowflake_3.STL

And here's a photo of the completed products.

Koch Snowflake Ornaments
Click to embiggen

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