In a rejoinder to Gill et alia (2021), Martin (2022) accuses us of perpetuating misconceptions about human nutrition and erroneously describing geophytes as a dietary staple. We provide authoritative definitions for the terms “essential” and “dietary staple” to show that it is Martin who mischaracterizes and misunderstands the foundational role of geophytes and other plant foods to human diets and subsistence economies in Native North America outside of the Arctic. Recent data demonstrate that carbohydrate-rich geophytes were abundant, regularly utilized, and essential resources on the Northern Channel Islands, a dietary staple that was a rich source of calories and complemented the protein-rich shellfish and finfish that were also staple foods for the Island Chumash.

There is growing evidence for human use of geophytes long before the advent of agriculture. Rich in carbohydrates, geophytes were important in many coastal areas where protein-rich marine foods are abundant. On California's Channel Islands, scholars have long questioned how maritime peoples sustained themselves for millennia with limited plant resources. Recent research demonstrates that geophytes were heavily used on the islands for 10,000 years, and here we describe geophyte and other archaeobotanical remains from an approximately 11,500-year-old site on Santa Rosa Island. Currently the earliest evidence for geophyte consumption in North America, our data extend geophyte use on the Channel Islands by roughly 1,500 years and document a diverse and balanced economy for early Paleocoastal peoples. Experimental return rates for a key island geophyte support archaeological evidence that the corms of blue dicks (Dipterostemon capitatus) were a high-ranked staple resource throughout the Holocene.

Forty years ago, Knut Fladmark (1979) argued that the Pacific Coast offered a viable alternative to the ice-free corridor model for the initial peopling of the Americas—one of the first to support a “coastal migration theory” that remained marginal for decades. Today, the pre-Clovis occupation at the Monte Verde site is widely accepted, several other pre-Clovis sites are well documented, investigations of terminal Pleistocene subaerial and submerged Pacific Coast landscapes have increased, and multiple lines of evidence are helping decode the nature of early human dispersals into the Americas. Misconceptions remain, however, about the state of knowledge, productivity, and deglaciation chronology of Pleistocene coastlines and possible technological connections around the Pacific Rim. We review current evidence for several significant clusters of early Pacific Coast archaeological sites in North and South America that include sites as old or older than Clovis. We argue that stemmed points, foliate points, and crescents (lunates) found around the Pacific Rim may corroborate genomic studies that support an early Pacific Coast dispersal route into the Americas. Still, much remains to be learned about the Pleistocene colonization of the Americas, and multiple working hypotheses are warranted.

In the face of environmental uncertainty due to anthropogenic climate change, islands are at the front lines of global change, threatened by sea level rise, habitat alteration, extinctions and declining biodiversity. Islands also stand at the forefront of scientific study for understanding the deep history of human ecodynamics and to build sustainable future systems. We summarize the long history of human interactions with Polynesian, Mediterranean, Californian and Caribbean island ecosystems, documenting the effects of various waves of human settlement and socioeconomic systems, from hunter–gatherer–fishers, to agriculturalists, to globalized colonial interests. We identify degradation of island environments resulting from human activities, as well as cases of human management of resources to enhance productivity and create more sustainable systems. These case studies suggest that within a general global pattern of progressive island degradation, there was no single trajectory of human impact, but rather complex effects based on variable island physiographies, human subsistence strategies, population densities, technologies, sociopolitical organization and decision-making.

Sea-level rise during the late Pleistocene and early Holocene inundated nearshore areas in many parts of the world, producing drastic changes in local ecosystems and obscuring significant portions of the archeological record. Although global forces are at play, the effects of sea-level rise are highly localized due to variability in glacial isostatic adjustment (GIA) effects. Interpretations of coastal paleoecology and archeology require reliable estimates of ancient shorelines that account for GIA effects. Here we build on previous models for California's Northern Channel Islands, producing more accurate late Pleistocene and Holocene paleogeographic reconstructions adjusted for regional GIA variability. This region has contributed significantly to our understanding of early New World coastal foragers. Sea level that was about 80-85 m lower than present at the time of the first known human occupation brought about a landscape and ecology substantially different than today. During the late Pleistocene, large tracts of coastal lowlands were exposed, while a colder, wetter climate and fluctuating marine conditions interacted with rapidly evolving littoral environments. At the close of the Pleistocene and start of the Holocene, people in coastal California faced shrinking land, intertidal, and subtidal zones, with important implications for resource availability and distribution.

The island fox (Urocyon littoralis) is one of few reportedly endemic terrestrial mammals on California's Channel Islands. Questions remain about how and when foxes first colonized the islands, with researchers speculating on a natural, human-assisted, or combined dispersal during the late Pleistocene and/or Holocene. A natural dispersal of foxes to the northern Channel Islands has been supported by reports of a few fox bones from late Pleistocene paleontological localities. Direct AMS 14C dating of these “fossil” fox bones produced dates ranging from ∼ 6400 to 200 cal yr BP, however, postdating human colonization of the islands by several millennia. Although one of these specimens is the earliest securely dated fox from the islands, these new data support the hypothesis that Native Americans introduced foxes to all the Channel Islands in the early to middle Holocene. However, a natural dispersal for the original island colonization cannot be ruled out until further paleontological, archaeological, and genetic studies (especially aDNA [ancient DNA]) are conducted.

Glassow’s (2015) synthesis of “red abalone middens” on California’s Santa Cruz Island does not include the broader geographic, chronologic, and ecological context to this phenomenon. We explore the wider distribution of these site types and emphasize their importance for addressing modern fisheries management issues.

Evidence for aboriginal whale hunting, long thought to be a practice limited to Northwest Coast tribes in northern Washington and British Columbia’s Vancouver Island, was previously reported at the Par-Tee site on the Oregon coast between about cal AD 620 and 990. An age estimate for a humpback whale phalanx with an embedded elk bone harpoon point was based on radiocarbon dates on charcoal not directly associated with the whale bone. We present high-resolution accelerator mass spectrometry (AMS) 14C dates for purified bone collagen extracted directly from the whale phalanx and embedded harpoon point. A calibrated date for the harpoon point places the whale hunting event between about cal AD 430 and 550. The apparent 14C age of the whale bone is estimated to be 220±37 14C yr older than the marine model age at that time, consistent with values from the eastern Pacific. These new dates suggest that whale hunting took place on the Oregon coast as much as 200–500 yr earlier than previously reported and more than a millennium before historic contact in the region. Our research highlights the significance of museum collections and high-resolution AMS 14C dating for addressing a variety of issues related to ancient archaeological sites and cultures.

The geographic and chronological distribution of eyed bone needles in North American Paleoindian sites led Osborn (2014) to propose that these distinctive artifacts date primarily to the Terminal Pleistocene Younger Dryas Cold Event and were essential to making close-fitting clothes needed to survive frigid winter conditions. Our study of a museum collection from Tule Lake Rock Shelter (CA-SIS-218A) in the high Klamath Basin area supports Osborn’s argument. We present nine high-precision accelerator mass spectrometry (AMS) radiocarbon assays from a 2.5 m deep cultural sequence, demonstrating that Paleoindians occupied the site primarily during the Younger Dryas. Although only about .5 m3 of the Paleoindian deposits at CA-SIS-218A were excavated, fragments of four small bone needles were recovered, three of which contain whole or partial eyes. Two fragments of large mammal cortical bone from the same levels contain remnants of “groove and snap” fractures that may be related to the production of needle blanks. The bone needles from Tule Lake Rock Shelter extend the geographic range of these distinctive Paleoindian artifacts into the high desert region of Northern California.

Fauvelle (2013) used experimental approaches to evaluate whether acorns were an important commodity traded from mainland groups to the Island Chumash. Consistent with a dearth of acorn remains found in island sites, he concluded that acorns were not a major export. We agree with this conclusion, but Fauvelle never adequately explains why acorns were not a major trade item and proposes that trade for high-quality asphaltum, supposedly unavailable on the islands, drove an intensification of Chumash social complexity. We believe the Island Chumash had abundant local plant foods, asphaltum, and other resources.

Using several methods to distinguish dart and arrow points, archaeologists have suggested that the bow and arrow appeared in various parts of the world between ˜65,000 and 1,000 years ago. Hildebrandt and King (2012) proposed a dart-arrow index (DAI) to help differentiate dart and arrow points, rejecting claims that the bow and arrow was introduced to western North America prior to the Late Holocene. We used the DAI and other methods to evaluate ˜11,700-year-old projectile points from Santa Rosa Island, obtaining mean values below the threshold for darts, comparable to several North American arrow point types. We have no direct evidence that these small points were used on darts, arrows, or hand-thrown spears, but faunal associations suggest that they may have served as harpoon tips used on atlatl darts to capture birds, fish, and marine mammals. The DAI and other methods for discriminating between dart and arrow points are based almost exclusively on ethnographic and archaeological specimens from interior regions. Our analysis suggests that such methods should not be applied universally, especially in coastal or other aquatic settings, and that archaeologists should continue to critically assess the antiquity of the bow and arrow and the function of projectile points worldwide.

In an important paper, O'Connor et al. (2011) described evidence for marine fishing from around 42 000-year-old (cal BP) deposits at Jerimalai Shelter on Timor-Leste. The paper's title referred to evidence for pelagic fishing and the maritime skills of anatomically modern humans (AMH). Considering that not long ago human seafaring and marine fishing were considered to be limited to the terminal Pleistocene or early Holocene (see Erlandson 2001), the paper's broader significance lies in the further evidence for Pleistocene voyaging required to colonise Timor-Leste and the quantities of fish bone that represent a substantial marine fishing effort at a relatively early date.

At the close of the Pleistocene, fire regimes in North America changed significantly in response to climate change, megafaunal extinctions, anthropogenic burning and possibly, even an extraterrestrial impact. On California's Channel Islands, researchers have long debated the nature of late Pleistocene “fire areas,” discrete red zones in sedimentary deposits, interpreted by some as prehistoric mammoth-roasting pits created by humans. Further research found no evidence that these red zones were cultural in origin, and two hypotheses were advanced to explain their origin: natural fires and groundwater processes. Radiocarbon dating, X-ray diffraction analysis, and identification of charcoal from six red zones on Santa Rosa Island suggest that the studied features date between ~ 27,500 and 11,400 cal yr BP and resulted from burning or heating, not from groundwater processes. Our results show that fire was a component of late Pleistocene Channel Island ecology prior to and after human colonization of the islands, with no clear evidence for increased fire frequency coincident with Paleoindian settlement, extinction of pygmy mammoths, or a proposed Younger Dryas impact event.

For at least 100,000 yr, marine shell beads have been important ornamental and symbolic artifacts intimately associated with the behavior of anatomically modern humans. In California, giant rock scallop (Hinnites multirugosus) beads were once thought to have been used only for the last 1000 yr, where they were considered to be markers of high social status among the Chumash Indians of the Santa Barbara Channel region. Direct accelerator mass spectrometry (AMS) radiocarbon dating of 1 giant rock scallop ornament and 2 beads from San Miguel Island extends the use of this shell for personal adornment to at least 8000 cal BP. Our study emphasizes the importance of direct AMS 14C dating of artifacts to enhance cultural chronologies and clarify the antiquity of various technologies and associated behaviors. Our results also caution archaeologists when equating artifact rarity with sociopolitical complexity.

Within the broad framework of historical and behavioral ecology, we analyzed faunal remains from a large habitation site (CA-SRI-147) on Santa Rosa Island to explore a 7,000 year record of coastal subsistence, nearshore ecological dynamics, and human impacts on shellfish populations. This long, stratified sequence provides a rare opportunity to study the effects of prolonged human predation on local intertidal and nearshore habitats. During the past 7,000 years, the Island Chumash and their predecessors had significant impacts on nearshore ecosystems, caused by growing human populations and depletion of marine and terrestrial ecosystems. At CA-SRI-147, local depletion of higher ranked shellfish species stimulated dietary expansion and a heavier reliance on lower-ranked shellfish taxa and more intensive exploitation of nearshore and pelagic fishes. In the Late Holocene, as local ecosystems were increasingly depleted, the Island Chumash relied increasingly on craft specialization and trade to meet their subsistence needs. Native peoples clearly impacted Channel Island ecosystems, but data from CA-SRI-147 suggest that they adjusted their subsistence strategies toward productive fisheries that sustained the high population densities and sociopolitical complexity recorded by early Spanish chroniclers at European contact.

In the journal Radiocarbon, Hall et al. (2005:383) claim that 35-CS-9, located in Bandon Ocean Wayside State Park on the southern Oregon coast, is one of the few Oregon coast sites “that includes sediments and artifacts dating to the early Holocene and possibly to the late Pleistocene.” Their claim for an early Holocene or late Pleistocene human occupation rests on a single radiocarbon date of 11,000 ± 140 BP (12,710–12,680 cal BP) taken from charcoal found at least 20 cm below the nearest artifact. Although Hall et al. compile various kinds of geoarchaeological evidence to support this claim, their case is not convincing. While we applaud aspects of their analyses, the inferences they have drawn are not substantiated by the evidence they present. We agree that 35-CS-9 is a significant site but believe claims for the antiquity of its human use have been exaggerated.

We demonstrate variable radiocarbon content within 2 historic (AD 1936) and 2 prehistoric (about 8200 BP and 3500 BP) Mytilus californianus shells from the Santa Barbara Channel region, California, USA. Historic specimens from the mainland coast exhibit a greater range of intrashell variability (i.e. 180–240 14C yr) than archaeological specimens from Daisy Cave on San Miguel Island (i.e. 120 14C yr in both shells). δ13C and δ18O profiles are in general agreement with the up welling of deep ocean water depleted in 14C as a determinant of local marine reservoir correction (ΔR) in the San Miguel Island samples. Upwelling cycles are difficult to identify in the mainland specimens, where intrashell variations in 14C content may be a complex product of oceanic mixing and periodic seasonal inputs of 14C-depeleted terrestrial runoff. Though the mechanisms controlling ΔR at subannual to annual scales are not entirely clear, the fluctuations represent significant sources of random dating error in marine environments, particularly if a small section of shell is selected for accelerator mass spectrometry (AMS) dating. For maximum precision and accuracy in AMS dating of marine shells, we recommend that archaeologists, paleontologists, and 14C lab personnel average out these variations by sampling across multiple increments of growth.

California's San Miguel Island contains over 600 archaeological sites, some occupied as early as 12,000 yr ago and most located along the island's north coast. Archaeologists have long believed the south coast to have been marginal or largely uninhabited. Burial of some landforms by sand dunes deposited after historical overgrazing, the lack of systematic survey, and a dearth of radiocarbon dating have also contributed to an underestimation of the intensity of human land use along the south coast of San Miguel Island. Our recent reconnaissance and dating of shell middens on the island's south coast indicate more intensive occupation than previously thought, with numerous south coast sites spanning at least the past 9000 yr, and demonstrate the utility of combining systematic archaeological reconnaissance and radiometrics in reconstructions of human settlement and historical ecology in coastal environments.