Nothing Is As Tender As Annotating Your Favourite Books. It’s Like Leaving A Piece Of Your Heart On

Hello! Why did penguins evolve to have black feathers if they live in icy (mostly white?) locations? I understand them having a white tummy because when swimming they could be more difficult to identify by a predator swimming below them? Thanks!

Love your blog!

Hello! So, here's what I learned at uni:

the widely-accepted reason penguins have black feathers is the same reason they have white tummies, but backwards. When swimming, they are more difficult to identify by a predator swimming above them! You can see similar countershading in sharks and dolphins, and also on land animals like mountain goats and lizards. Overall, it helps to make animals less obvious when viewing from the side, because it reduces the obviousness of their shadow.

As to why penguins have black feathers in icy, mostly white, locations (on LAND), you need to consider why it would be good to be white in an icy, white location in the first place!

Mostly, it would provide camouflage, which would protect from land predators! However, penguins don't really have any significant land predators in Antarctica. There are no polar bears, or big snakes, or even foxes or coyotes in Antarctica, so the penguin won't benefit from being camouflaged on land. Basically, there's no "selective pressure" for them to be all white!

some penguin chicks, however, do have to worry about a few predators, so they have a little more camouflage than the adult penguins:

What's more, there are likely advantages to black feathers in a cold environment like Antarctica! For example, in the sun, dark feathers absorb more thermal energy, helping to warm the penguin and maintain their body heat.

There may also be some stuff with black feathers being more resistant to wear/ friction drag in the water, but that's entering the realm of ongoing research, which I won't get into here.

Let me know if there's anything that needs clarifying!

(some citations if anyone wants further reading:)

Bonser, R. H. (1995). Melanin and the abrasion resistance of feathers. The Condor, 97(2), 590-591.

Ksepka, D. T. (2016). The penguin's palette--more than black and white: this stereotypically tuxedo-clad bird shows that evolution certainly can accessorize. American Scientist, 104(1), 36-44.

Rowland, H. M. (2009). From Abbott Thayer to the present day: what have we learned about the function of countershading?. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1516), 519-527.

Zagrai, A., & Hassanalian, M. (2020, July). Penguin coloration affects skin friction drag. In 2020 Gulf Southwest Section Conference.

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oblivious

A portrait in blood vessels. Magnetic resonance angiography (MRA) is a specialised medical imaging technique used to visualise blood vessels. Here, tangled white tubes represent the major blood vessels of the head, neck and upper thorax. Looking at the uppermost portion of the image, one can see the silhouette of the brain whilst the aortic arch takes the center bottom. All these vessels are hard at work beneath your skin, even as you read this post. 

Feeling like a pro in Atomic Force Microscopy

...to be honest I probably should really tell myself that at this point I really am the professional in this method. After 4 years of working with 2 different atomic force microscopes, now I started with a 3rd one, again a new type from a different company.

Only after 2 hours of training on the new machine, I could observe membranes of resistant bacteria all by myself. The membranes are the yellow pancakes sitting flat on the dark support. They are less than 8 nm high (0.000000008 m), as is visible in the blue and red profile lines. So it's super tricky to actually see them. Atomic force microscope touches the surface of my membranes and surrounding support with a tiny tip like with a finger and reconstructs the surface topology. On top of the small size, the cellular membranes are super soft so also the touching finger must be super soft to see them without damaging them.

I've read a few things recently on how people categorize everything ( by colors, forms, animal kingdoms...) naming something is bringing it in existence , giving it definition and making it different from all the other things. Words are containers of concepts, we see ourselves as being contained within the body, within the space or time. We put invisible borders around things and define them as a way to bring them into existence.

there is no greater joy on this earth than Making Lists, Categorizing, & Sorting

What are Phytoplankton and Why Are They Important?

Breathe deep… and thank phytoplankton.

Why? Like plants on land, these microscopic creatures capture energy from the sun and carbon from the atmosphere to produce oxygen.

Phytoplankton are microscopic organisms that live in watery environments, both salty and fresh. Though tiny, these creatures are the foundation of the aquatic food chain. They not only sustain healthy aquatic ecosystems, they also provide important clues on climate change.

Let’s explore what these creatures are and why they are important for NASA research.

Phytoplankton are diverse

Phytoplankton are an extremely diversified group of organisms, varying from photosynthesizing bacteria, e.g. cyanobacteria, to diatoms, to chalk-coated coccolithophores. Studying this incredibly diverse group is key to understanding the health - and future - of our ocean and life on earth.

Their growth depends on the availability of carbon dioxide, sunlight and nutrients. Like land plants, these creatures require nutrients such as nitrate, phosphate, silicate, and calcium at various levels. When conditions are right, populations can grow explosively, a phenomenon known as a bloom.

Phytoplankton blooms in the South Pacific Ocean with sediment re-suspended from the ocean floor by waves and tides along much of the New Zealand coastline.

Phytoplankton are Foundational

Phytoplankton are the foundation of the aquatic food web, feeding everything from microscopic, animal-like zooplankton to multi-ton whales. Certain species of phytoplankton produce powerful biotoxins that can kill marine life and people who eat contaminated seafood.

Phytoplankton are Part of the Carbon Cycle

Phytoplankton play an important part in the flow of carbon dioxide from the atmosphere into the ocean. Carbon dioxide is consumed during photosynthesis, with carbon being incorporated in the phytoplankton, and as phytoplankton sink a portion of that carbon makes its way into the deep ocean (far away from the atmosphere).

Changes in the growth of phytoplankton may affect atmospheric carbon dioxide concentrations, which impact climate and global surface temperatures. NASA field campaigns like EXPORTS are helping to understand the ocean's impact in terms of storing carbon dioxide.

Phytoplankton are Key to Understanding a Changing Ocean

NASA studies phytoplankton in different ways with satellites, instruments, and ships. Upcoming missions like Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) - set to launch Jan. 2024 - will reveal interactions between the ocean and atmosphere. This includes how they exchange carbon dioxide and how atmospheric aerosols might fuel phytoplankton growth in the ocean.

Information collected by PACE, especially about changes in plankton populations, will be available to researchers all over the world. See how this data will be used.

The Ocean Color Instrument (OCI) is integrated onto the PACE spacecraft in the cleanroom at Goddard Space Flight Center. Credit: NASA

Earth fractals from above