Updates for The Design of Life
New research puts more “wow” into the wonder of animals featured in Illustra Media’s “Design of Life” documentaries.
If you haven’t seen the nature documentaries by Illustra Media collected into its Design of Life trilogy, you can watch the trailers at our Recommended Resources page.
This Tiny Butterfly Can Fly a Record 2,500 Miles at a Time From Europe to Africa (National Geographic). Step aside, Monarch. The Painted Lady is now queen of the migrating butterflies. This dainty butterfly, smaller than the monarch and found on all continents except Antarctica and South America, breaks the record shown in Illustra’s film Metamorphosis: The Beauty and Design of Butterflies (although that is still an awesome story). Whereas the Monarch takes several generations to get from Canada to Mexico and back, some painted ladies can make their cycle in a single generation. Patient scientists discovered the overwintering sites, reminiscent of Fred Urquhart’s tracking of the Monarch home in Mexico in 1976:
Scientists already knew the painted ladies that blanket North America in the warmer months migrate to Mexico and Central America during the winter.
They’ve also tracked Eurasian painted ladies as far south as the Sahara, but then the butterflies disappear off the map. Talavera and Vila knew they had to be somewhere in tropical Africa.
Lo and behold, in Chad, Benin, and Niger, Talavera and Vila found vast swarms of painted ladies overwintering in the warmer climes—as many as 20,000 butterflies per hectare.
The discovery proves that the two-inch butterfly can migrate nearly 2,500 miles from Europe, traversing such obstacles such as the Mediterranean Sea, North Africa’s mountains, and the Sahara Desert.
This makes it the “longest continuous butterfly migration ever recorded,” the article says. For entomologist Gerard Talavera, who has traveled through Spain and Africa tracing the migration path, the discovery is astonishing. “It’s a common butterfly that does some really unique and amazing things,” he says.
Unlike monarchs, painted ladies don’t always migrate every year, or go to the same spot. They also fly at a higher altitude. “Painted ladies can, but don’t always, make the migration in a single generation,” the article says. They can also breed along the way. Perhaps this flexibility gives them more options than monarchs, whose numbers decline when their forest habitat in Mexico becomes reduced from logging.
It’s not only size, but scales that matter in some male moth antennae (Science Daily). The scale patterns on the antenna of a male moth are exquisitely patterned to capture faint scents of female pheromones, says this report. This adds finesse to a story on Evolution News about how the antennae of cockroaches are patterned to capture information on both the shape and temporal changes of odor plumes. (This story was also picked up by World Magazine.)
Instead of focusing on the design, this article compliments Charles Darwin for thinking that male antenna might be subject to ‘sexual selection’ for elaborate patterns. But then, the article notices an “evolutionary dilemma” in that not all moth species have the feather-like pattern. By analyzing the patterns with electron microscopes, Professor Mark Elgar noticed that the shape of individual scales is able to concentrate odorants around the olfactory neurons on the antennae. He still gave credit to Darwin in the end. “It’s fascinating that Darwin’s theory is still supported, but we needed modern techniques such as electron microscopy and computational fluid dynamics to confirm that it is antennal scales, and not size that make them more effective and detecting those crucial sex pheromones,” said Professor Elgar with pomp but without circumstance.
Black Jacobin hummingbirds vocalize above the known hearing range of birds (Current Biology). Hummingbirds starred in Illustra’s film Flight: The Genius of Birds. We tend to think more of humming than singing by these birds, but this paper reveals a new trick by one species, the black Jacobin that lives in the Brazilian mountains. The open-access paper describes their unusually high-pitched songs:
Hummingbirds are a fascinating group of birds, but some aspects of their biology are poorly understood, such as their highly diverse vocal behaviors. We show here that the predominant vocalization of black jacobins (Florisuga fusca), a hummingbird prevalent in the mountains of the Brazilian Atlantic Forest, consists of a triplet of syllables with high fundamental frequency (mean F0 ∼11.8 kHz), rapid frequency oscillations and strong ultrasonic harmonics and no detectable elements below ∼10 kHz. These are the most common vocalizations of these birds, and their frequency range is above the known hearing range of any bird species recorded to date, including hearing specialists such as owls. These observations suggest that black jacobins either have an atypically high frequency hearing range, or alternatively their primary vocalization has a yet unknown function unrelated to vocal communication. Black jacobin vocalizations challenge current notions about vocal communication in birds.
Their first reaction is to suggest an evolutionary explanation for their divergence from other hummingbirds. This required raising the perhapsimaybecouldness index into the ultrasonic level. In the end, though, they don’t know why this species sings at such a high pitch.
Black jacobins belong to the little studied and species-poor Topaz clade, having diverged from all other hummingbird clades ∼22 million years ago, and their distribution along the Brazilian Atlantic coastal forest coincides with one of the oldest and biodiverse biomes on the planet. It is intriguing to think that such a diverse environment may have created acoustic constraints that helped shape vocal communication, which includes coexistence with up to ∼40 other hummingbird (sub-)species. This could have led to a substantial vocal-auditory shift in black jacobins, as shown in some amphibians and reptiles. Alternatively, if their hearing sensitivity is not shifted, their high frequency vocalizations may serve other functions. Either scenario is fascinating and warrants further studies of this species in its natural context.
If the environment or competition “could” have led to this pitch shift, why didn’t some hummingbirds evolve very low bass songs in the infrasonic level? And why didn’t every creature in the forest respond to the same environmental pressure? The assumption that an environment can somehow create complex behaviors or functions stretches the Stuff Happens Law to the limit (see 13 March 2018 entry).
Living Waters Update
Male loggerhead turtles also go back to their nesting beaches to breed (Science Daily). Illustra’s film Living Waters: Intelligent Design in the Oceans of the Earth contains unforgettable scenes of mature sea turtles climbing up the beach to dig holes in the sand and lay their eggs, often 30 years after they emerged from the same beaches as hatchlings. Since female sea turtles lay the eggs, it was long thought that they were the ones who would migrate long distances to the natal beaches. Now, though, scientists from the University of Barcelona have documented that male sea turtles of the loggerhead species (Caretta caretta) also go the distance. It’s a “new paradigm,” the article says:
It was believed that only female turtles went back to the nesting areas to lay the eggs -philopatric behaviour- after reproducing with male turtles from different areas. Philopatry is a studied phenomenon among female C. caretta turtles. The process of detection, marking, and the chelonian genetic study (for instance, with the mitochondrial DNA, transmitted by maternal inheritance), are easily conducted if females are the ones that go back to the beach of birth to lay the eggs.
However, markers in males are not abundant and results have never been conclusive. Previous studies with few genetic nuclear markers ─microsatellite loci, the biparental inheritance─ suggested male turtles did not show philopatric behaviour and mated with females from different areas.
“Our study reveals the breeding behaviour of the C. caretta marine turtle can be more complex. In most populations, female turtles are not the only ones with philatropic behaviour: males also mate near nesting beaches,” says the lecturer Marta Pascual, member of the Department of Genetics, Microbiology and Statistics of the UB and IRBio.
For sea turtles, temperature determines sex. “The sex of marine turtles is determined by the temperature of incubation,” the article explains. “If the temperature is high, there will only be female turtles.” It’s possible that the location of fertilization varies. “There are still many unknown issues on the breeding biology of the species” of loggerheads, the article concludes.
Update 3/16/18: Sea turtles are doing well in Nicaragua thanks to conservation efforts, reports Phys.org. The article has pictures and descriptions of the primary members of 7 known species.
Illustra’s beautiful Design of Life documentary films belong in every nature lover’s library. But now, as DVDs continue to decline in market share, selected clips are becoming available online, as listed below—and full length versions are available for streaming from iTunes and Amazon. Still, it helps Illustra stay in business when supporters purchase DVDs of their films at the authorized distributor, Go2RPI.com. There, you can buy individual films, or sets of three attractively packaged as a trilogy. You can also purchase quicksleeve copies in quantity to use as ministry giveaways. If you love Illustra Media‘s work (and who doesn’t), consider becoming a regular contributor. Join their mailing list to receive monthly newsletters. You can also follow them on Facebook and on Twitter with the name @illustramedia.
To view selected clips from the films, here’s where to find them online:
Exciting News! Foreign Language Translations. Speakers of French, Spanish or Portuguese can now see these films in their entirety on YouTube. In addition, these languages plus Mandarin can be ordered through Go2RPI.com. These translations were done by professional narrators with lip-sync accuracy, and retain all the beauty of the visuals and music of the originals. They also come with English or foreign-language subtitles. Spread the word to your non-English-speaking contacts!